Hi Mina,
Welcome to the Mattress Forum! 
I’m very happy that you’ve found us and that the information here has been helpful.
Savvy Rest does use good quality materials in their mattresses, but they can be offered by some retailers in a bit of a higher price point, so it is something about which you’d want to make a careful value equation about when performing your overall mattress research.
You didn’t mention the configuration you enjoyed when sampling the Savvy Rest product (Dunlop or Talalay, combination order of firm, medium or soft layers, or what mattress combination you sampled – Serenity or Unity), so I can’t comment upon that, nor compare to the SleepEZ samples you received, as you don’t mention what those are as well (Talalay or Dunlop, blended or natural, ILDs). The samples normally provided by Savvy Rest are small cubes, like building bocks. I’m not sure what SleepEZ sent out to you if you requested samples as far as size goes. If you are finding them a bit “bouncy” (all latex will be quite bouncy, as it is foamed rubber), you may be describing Talalay samples, as it tends to be a bit “bouncier” than Dunlop. They could also be softer because they are a lower ILD than the Dunlop you are comparing, or they could be at the same ILD, with the Dunlop feeling a bit firmer as it is compressed deeper. Without more specific information I can only speak in general terms.
Dunlop and Talalay aren’t directly comparable in terms of firmness using only ILD numbers because there are several factors that can affect how soft or firm a mattress (or an individual layer) feels besides just the ILD of the material (see post #4 here) and Dunlop and Talalay that are the same thickness and ILD won’t feel the same in terms of their firmness for most people because they have a different response curve and compression modulus (how quickly a material becomes firmer as you sink into it more deeply).
There is also more about the difference between Dunlop and Talalay in post #7 here.
My best recommendation would be to contact SleepEZ with the exact layering that you enjoyed in the Savvy Rest that you sampled, and they would be able to approximated those layers to create a comfort that would be “in the ballpark” of what you sampled. They are familiar with the Savvy Rest product. If you’re considering a queen or a king mattress, you could also customize the left and right sides with different layers and styles of latex to meet individual comfort preferences.
Yes, the covering will impact the overall comfort of the product. The covering used by Savvy Rest is a bit on the stiff side (it does break in as time goes on), but even a thinner “stretch-knit” covering will still impact the overall comfort of the mattress. And it could be that you prefer the feel of Dunlop over Talalay, but again I don’t know what you sampled in the showroom you visited.
While you can’t tell overall comfort from a few small sample pieces of latex, it does give you a bit of an indication of the properties of the material you are considering. Some people are more sensitive to the buoyancy of the different styles of latex than others, so there’s certainly nothing wrong with having your own personal preference. Either way, you’d be making a decision using good quality and durable materials. And I would recommend a phone call, not an email, when going over details of potential configurations, as you can provide more accurate information in real-time and get more detailed and a higher volume of information in a much shorter period of time.
Your husband is definitely in a higher BMI range than you, so a split left/right configuration could prove useful in your situation. A higher BMI presents special challenges and generally requires firmer materials (in the support layers especially). This certainly could be firmer latex. Higher BMI people in general will need firmer and thicker comfort layers and firmer support layers than those who are lighter and because no materials will last as long with much higher weights the quality and durability of the materials and components is even more important than normal. I wouldn’t “rule out” any types of mattress and base your choices on your own personal testing. Post #3 here has more information and suggestions about heavier weights that is worth reading.
The main benefit of a thicker latex mattress is that it can be more adaptable for heavier weights and multiple sleeping positions. It will compress from softer to firmer more gradually which means that there is more “range” of compression without the mattress becoming too firm for heavier weights (or parts of the body). It can even just be a matter of preference rather than “need”. If you can imagine for example a 2" layer of latex (or any foam material) on the floor you would compress it to it’s maximum and feel much more of the floor (it goes from soft to maximum compressed firmness within the space of a 2" layer) but if you had the same softness of latex in a 6" layer on the floor … it would feel much softer and compress more gradually and to a lesser percentage of its overall thickness and wouldn’t reach the same level of firmness or “bottom out” (which means reaching the maximum level of compression or firmness that a layer or a mattress can effectively achieve).
In the large majority of cases … 8" - 9" of latex is easily enough to include the combination softer layers (or sometimes sections) for pressure relief and firmer layers for support that most people of average or even higher weights would need. In some cases … lighter weights or people that sleep in “flatter” sleeping positions, have slimmer less curvy body types, or who prefer a firmer mattress will do well with even 6" even though there is less “room” to design in different layers in the mattress. People that have much higher body weights or larger body types may choose more than the “average” thickness and may prefer the feel and extra adaptability of say 12" of latex. Thicker mattresses can also use firmer materials because thickness and softness are very related and work together. These are all good questions to ask the manufacturer or retailer of a mattress so they can discuss the differences between the different options they have available in terms that are more specific to the layers they use or options they provide.
I don’t know what types/styles/ILDs of latex samples you had or their ordering, but applying a specific weight to a small sample will not be representative of how a product will feel or react in a “real world” setting, as your weight will be spread out over a wider area and the foam will also be able to spread that mass over a wider area and also draw upon the cell structure of the larger overall piece of foam used in a finished mattress, so a complete compression of a latex layer, even the uppermost layer, will not happen in a finished mattress.
All the layers of a mattress actually compress simultaneously not sequentially and they will each compress to different percentages of their thickness depending on their position on the mattress, the firmness of each layer, the compression modulus of the material, the thickness of each layer, and the compression force that they are exposed to (which depends on the weight of the part of the body in contact with the mattress and the surface area that is bearing that weight which is constantly changing as you sink into the mattress more or change sleep positions).
While “going through” a layer is commonly used as a way to explain things because there is a different amount of force that “goes through” a layer and compresses the next layer of the mattress depending on the hysteresis of the material (how much energy it absorbs) and on how point elastic the material is (how much compression affects or is affected by the surrounding areas of the layer) … it would be just as accurate to say that you will “feel through” the top layer meaning that you will feel the properties of the next layer down to different degrees. Even the softest latex won’t “bottom out” (meaning it has no more ability to compress because the walls of the cell structure are fully compressed on top of each other) if it is on top of another foam layer and will have the ability to compress more yet even though very soft latex will compress to a much larger percentage of its thickness than a firmer layer. Every layer of a mattress affects and is affected by every other layer in the mattress to different degrees.
The compression of each layer (mainly controlled by thickness, firmness, compression modulus, hysteresis, and position along with a few other specs) are what creates the pressure relieving cradle of a mattress in the top layers which re-distributes weight and pressure on the bony prominences and pressure points of the body while the resistance to further compression of the deeper layers is what “stops” the heavier parts of the body from sinking down too far and putting the spine and joints out of their natural alignment. The balance between the opposing needs of pressure relief and spinal alignment is the main factor behind all mattress design and theory and why different mattresses match the body types and sleeping positions and preferences of different people … or don’t.
Without personal testing (which you did already with the Savvy Rest) and going through the learning curve of becoming familiar enough with different types of materials and layering and how they work in combination with each other to predict how a certain layering may work for you … you would be much better off simply going with the suggestions of a knowledgeable retailer or manufacturer who is familiar with how the different options they offer fits the “averages” of people who may be similar to you.
Overall, there is no formula that can predict with any certainty what type of layering you may do best with that can possibly be more accurate than your own personal experience.
If you have any other more specific questions, I’ll do my best to answer them, but my best suggestion would be a phone call with SleepEZ and have your layering configurations on hand to provide them as to what you and your husband enjoyed from Savvy Rest.
I’ll be interested in learning about your progress.
Phoenix