Hi itsevie,
Welcome to the Mattress Forum! 
Let me start with saying that you have found a great resource in the Mattress Underground. Not only is there a wealth of knowledge on this site, TMU has many trusted members with quality products that could be a good fit for you and can hopefully help you achieve more restful sleep.
To start, you can read over the Mattress Undergrounds Shop Tutorial here as your first step for an overview. Next, this article here is a good reference to explore the quality and durability of a mattress, if it has any weak links in terms of its design, and also discusses BMI.
Based on your needs described, having you feel comfortable is key for your pain, but also you need a mattress that will provide proper support. Your wedge pillow sounds like it could help to keep you elevated, and an adjustable base is also a great investment if the wedge does not sustain comfort. Adjustable bases can range from very basic, providing up and down motion, to having all the bells and whistles including massage, USB ports, pillow tilt, etc. It would be good to determine which features are important to you, compared to the price point.
When it comes to pressure point relief, memory foam or latex are great choices. It just depends on which type of material you prefer the feel of, and the quality you value more. Post #2 here is helpful since it explains the different ways to choose a suitable mattress that is the best “match” for you in terms of “comfort.”
Mattresses with options to flip or rearrange layers are very beneficial. They allow the customer to easily change up the feel after purchase if needed without spending more money. This is what our company personally provides and it works great. Customizable and allows for rearranging.
Hope this helps! Please let us know if you have any further questions.
Foam Sweet Foam Support Team
