Hi Bad1,
The first place to start (in case you haven’t read it) is post #1 here which links to the most important information you will need and has a step by step process that can help you find the best mattress for YOU.
It sounds to me like you are on step 3 (identifying the better local sources) or step 4 (testing mattresses and various combinations of material and styles).
In case you haven’t seen it … the better choices and possibilities I’m aware of in the Greater Los Angeles area are listed in post #2 here (including Flexus and Electropedic).
With your weights and the health challenges you are facing it would be especially important if it was me to work with more knowledgeable people and to make sure you do very careful and more objective testing (some testing guidelines are in the first post I linked). Since it seems that you are looking primarily at latex … then I would first look at their websites and talk to the ones that most attract you or are closest to make sure they have a mattress that you want to test and then visit the ones that sound most promising in your initial phone conversation. If you do decide to go in the direction of looking at memory foam then I would make sure it was tested for offgassing by a reputable testing protocol (such as CertiPur). There are some good choices here as well. Who you work with can be just as important as what you buy when your circumstances are more challenging but you have some good choices available to you.
In terms of an adjustable bed … it seems like this would also be a good option for you both for health and comfort reasons and the adjustable bed thread here should be helpful in your choice. It also has some price references for all of the models that you mentioned that you can use for comparisons. Electropedic is also very knowledgeable about adjustable beds and carries many brands (and also sells latex mattresses).
When the suitability of your choice is as important as it would be for you … there are no shortcuts except some very careful testing along with working with more knowledgeable people who can help you make good choices but the good news is that you have some good options and manufacturers or retailers to work with.
Phoenix