Hi KevKanos,
There is more information in post #3 here and the posts it links to that would be helpful for those that are in higher weight ranges.
While the process of how to choose a mattress would be the same (see the mattress shopping tutorial here) … most people in higher weight ranges will generally need or prefer firmer mattresses (firmer materials will feel softer because you will sink into them more) and materials and components that are higher quality/density and more durable than those that are in lower weight ranges (the materials and components in a mattress will soften and break down faster for those in higher weight ranges than they will for someone that is in a lower weight range that doesn’t compress the mattress as deeply).
I would be cautious about mattresses that use more than “about an inch or so” of memory foam that is less than about 5 lb density or polyfoam that is less than about 2 lb density … particularly in the upper layers of the mattress.
Phoenix