Hi dastur,
One of the most effective ways that can accommodate more difficult body types is different types of zoning. This can allow for the use of firmer support under the heavier parts of the body like the pelvis and still allow for the use of thicker / softer materials under your wider but lighter shoulders that can “allow” them to sink in more deeply while still supporting and “holding up” the heavier pelvis.
The materials and the “feel” of the mattress are more a matter of preference and don’t matter nearly as much as the design of the mattress and how well it can provide for different levels of support or pressure relief under each part of the body. There is more about zoning in this article and in [url= https://forum.mattressunderground.com/t/shooting-at-a-moving-target]post #11 here[/url].
Other factors such as the changing surface area of each part of the body relative to its weight as you sink in more deeply into the mattress and the compression modulus of different foam materials (how quickly a foam becomes firmer as you sink in more deeply) and the “point elasticity” of different materials can also play a role in the primary support, secondary support, and pressure relief of different mattress designs that can work well for different people in terms of PPP (see post #6 here and [url= https://forum.mattressunderground.com/t/latex-feel-ild-thickness]post #2 here[/url]). In some cases even something as seemingly simple as a mattress pad, mattress protector, or the type of cover or quilting in a mattress can affect how much a mattress can contour to each body shape or how well the shoulders can sink into the mattress.
I would also be cautious with airbeds and using air for support and you can see some of my thoughts about them in this article. At the very least it may be useful to have an airbed with a center zone that can be adjusted for firmness independently but even here they don’t have the same progressive firmness as foams, innersprings, or latex.
Phoenix