Hi hook13,
There are too many unknowns, variables, and personal preferences for anyone to make specific mattress suggestions for someone else (see mattress firmness/comfort levels in post #2 here) but I can certainly help with how to choose rather than what to choose.
With your weights it will be particularly important that the materials in your mattress are both suitable for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and durability because lower quality materials will soften and degrade much more quickly with higher weights and your most suitable choices may be different and require firmer layers than those that are lighter.
The first place to start is post #1 here which has all the information, steps, and guidelines that can help you make the best possible choices (and avoid the worst ones or any mattress where you aren’t able to find out the details of the materials inside it).
Once you get to step 3 some of the better options I’m aware of in the Chicago area are listed in post #2 and #4 here.
I would start (and probably end) with Quality Sleep / My Green Mattress which is one of the members here which means I believe they are among the best quality/value in the country.
Phoenix