Hi seigga22,
The best suggestion I could make would be to test a few mattresses in the Sacramento area that have known layerings (both in thickness and ILD) to get a more clear sense of the layering that would work best for both of you. Because of your weight differential … you would also likely be a good candidate for a split construction where each side of the mattress has a different ILD and it would be a good idea for each of you to find the layering that worked best. European Sleep Design would be a good place to do this testing because they have different options for both the comfort layers and the support layers in each mattress and they are open about the layers in each of their mattresses.
Post #5 here would also give you some good places to do some testing so you can get as close as you can to the optimal layering for each of you either for an actual purchase or as a prototype for an online purchase. Bear in mind that local testing (done correctly) is always more accurate than “theory at a distance”.
Your lower weight would normally suggest a softer latex on the top for good pressure relief on your side. Your DH’s higher weight would normally suggest the need for a slightly firmer comfort layer because heavier people will sink in further into firmer form so it will feel softer to them. He also spends time on his stomach so this would also be another reason to go a little firmer if the pressure relief was still good for him.
Given your preference for thinner softer top layer … then a 2" comfort layer would seem to be a good option but I would make sure I had tested this type of layering to make sure it provided good pressure relief (at least 15 minutes on the mattress … fully relaxed on your side … and sensing for any pressure in either the hips or shoulders). The firmness of the layer below a 2" comfort layer will also make a difference in its pressure relieving qualities.
Latex in general is the coolest of all the foams because it has a more “on” rather than the more “in” the mattress feel of memory foam and it doesn’t wrap you as tightly as memory foam. It also has a more open cell structure which allows air to circulate more freely. Most people do fine either with or without wool in the quilting but of course this can vary greatly on an individual basis depending on how hot a person usually sleeps. Wool is more breathable than foam but it can also affect the feel and performance of any foam underneath it. You can read about some of the tradeoffs involved in choosing a quilted or unquilted ticking in this article and in post #16 here.
As far as the pros and cons of a tension adjustable slatted base … it would vary depending on the thickness of the mattress and the types of materials that were in it. In general though a slatted base (like all layers that are near the bottom of your sleeping system) will have a primary effect on spinal alignment and a lesser secondary effect on pressure relief. Because “comfort” is partly both of these in combination with the individual preferences of each person … it would be fair to say that it will affect the feel of the mattress but more in the alignment part than the pressure relief part. They are a great way to fine tune a mattress if necessary (by letting the shoulders sink down more or holding up the hips higher) as long as it’s not too thick for the adjustable base to have a noticeable effect. The most effective way to know how it will affect any mattress would be to test the mattress on a firm base (or even the floor) and then again on the adjustable base to see how the difference felt for you. Most of the feeling you would have felt from the Sleep Designs mattress would have been from the mattress but some of it could also have been from the base.
Hope this helps.
Phoenix