Hi Brooklyn Returnee, and welcome to The Mattress Underground 
First, I suggest, if you have not already done so, to take a look at themattress shopping tutorial, as well as the Mattress Specifications you need to know and the mattress durability guidelines to get a better idea of what to look for in a mattress, materials and components and see how they last over time. Any mattress you consider will feel different to different sleepers using it. This is based on the sleepers’ stats(height, BMI, sleeping position(s) and any underlying health issues) and their PPP(posture and alignment, pressure relief, and personal preferences). Thanks for providing your stats…As you are both higher BMI, and sleep on your sides and back, you need a good supportive mattress. You are shopping the correct way, by testing different types and materials to see what feels best to you both.
As for your questions: Berkley Ergonomics produced the Narvik for Jordons’ Furniture. It has as you say, a cotton with wool and camel hair cover, with 3 sets of coils (from top down: microcoils, minicoils, and Swedish pocket coils) and two layers of Talalay.
The camel/wool cover is a breathable, temperature regulating layer to allow air circulation between the sleepers and the latex. Camels (laminoids) can handle extreme temperature variations, UV exposure, moisture control. Aside from price which is a major consideration your choice for Camel hair surface based on sleeping hot is excellent. Unlike a wool pillow, which compresses with use, the quilted cover should not have noticeable meaningful ‘flattening’ with normal use for several reasons. The thickness of the top quilt usually accommodates for any compression over time of the quilt layers without detracting from the overall comfort. It will create a more superficial cradle that is not deep enough to affect comfort, then the layer of Camel hair (add linkhttps://www.berkeleyergo.com/camel-hair) is placed on top of the wool (from French plain-air sheep) used in the quilting has longer fibers and curlier which does not compress as easily and is superior in that respect to mechanically crimped wool fiber. You can read more about Camel hair advantages here Is Camel Hair Considered Wool? | Camelus | Sustainable Products (insert link)
I would be however concerned about the ¾ inch of soft latex on top of the micro coils as at your BMI is very likely to wear out much faster for higher weight range BMIs and you may start to feel coils below. Lower density latex (which will be softer) will break down much sooner. So I’d make a call and try to find out how this mattress holds up for heavier sleepers.
Aside from being much pricier, the McRoskey Sunset, like many major retail brands, are not transparent with details and specifications of their mattresses. It is a flippable mattress with a cotton/wool cover and pocketed innersprings. Without detailed info on the components, for the price, this raises red flags for me.
The Shifman Garrison is not only very expensive but it is likewise light on provided specifications on the density and materials used in their components; this is also a flippable hybrid with pocketed coils, wool and cotton cover, and latex with a cashmere comfort layer. Without specific details its’ difficult to comment on this.
As to whether a latex mattress will be ‘better’ for you – if you find a latex mattress comfortable, then the answer is yes; no one can tell you which type of mattress is ‘right’ for you both, except you. Larger sleepers do have to make sure they have proper support, along with comfort, which any good mattresses sakes associate should be able to advise on, My cautions on the last two above are that they are light on providing specifics, and are not inexpensive. While they may be fine, I cannot comment on their durability or continued comfort. If you are looking at other options or are considering online ordering, you may want to look at similar offerings by theTrusted membersof the site…by providing them a little info about you both they have much experience providing ideal mattresses to sleepers, and are completely transparent about the materials and details of their components to allow you to make a good choice. Many also carry a variety of foundations to complete your sleep system, or can advise on what sort of platform would be best for the mattress you choose
~ Basilio