Hi andrew,
The first place to start your research is post #1 here which has all the basic information, steps, and guidelines you will need to make the best possible choices … and avoid the worst ones.
When you have back issues … it’s even more important than normal to make sure that a mattress provides you with good spinal alignment in all your sleeping positions (even though it’s one of the most important parts of a mattress choice for all people). There is more about how to test for this in the read post I linked. Of course a mattress can’t solve a medical issue … but it can at least help with allowing all your muscles and body to relax and recover to the degree possible and help avoid making the symptoms worse and giving you the best quality sleep possible with your specific back issues.
I would avoid trying to design or choose the specifics of your mattress before you have done any testing. The softness/firmness of a mattress and terms like “medium firm” are subjective and not particularly meaningful. They are always relative to the body type, sleeping positions, sensitivity, and preferences of each person and how each person interacts with a specific mattress design. The goal is a mattress that matches your specific needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) in real life rather than in theory.
The reviews of other people that are not identical to you can be among the most misleading way to purchase a mattress because most people who post reviews have very little knowledge about mattresses or have any idea of the materials in the mattress they purchased. You can read more about reading mattress reviews vs mattress research in post #13 here.
Again reviews are not a particularly meaningful or accurate way to assess or choose a mattress. Airbeds use the same types of comfort layers or materials as any other mattress so the most meaningful way to compare an air bladder as a support layer is by comparing them to other types of support layers (not comparing the entire mattress which is a combination of materials). You can see my thoughts about airbeds and how air bladders compare to other support materials and components in this article.
No material relieves pain and any material in an appropriate design can keep you in alignment which is the key to back pain. The choice of materials or between different types of latex is a preference issue … not a better/worse issue. The key to good alignment is in the design of the mattress not the materials that are used.
Again … this is a preference issue not a “better/worse” issue and one is not better than another for back pain. It’s all a matter of the specific design of the mattress. There is more about the differences between blended and 100% natural talalay in post #2 here. both are great materials for different reasons and preferences.
Again … the choice of types of latex is a matter of preference. You can read more about the different types and the differences between them in this article and in post #6 here and there is more about the different “feel” of Talalay and Dunlop in post #7 here but this is all preference and would be based on which one you prefer in your own experience and which of the different qualities that make each of them different are most important to you. It’s like asking which type of fruit is the best which of course has no real answer.
Some of the better options and possibilities I’m aware of in the Seattle/Tacoma region are listed in post #2 here
Phoenix