Hi g1981c,
One of the posts I linked for you earlier was post #1 here which includes all the information, steps, and guidelines that can help you make the best possible choice.
Step 3 in that post is all about the importance of working with the “experts” and finding the better options in your area and how to find them. When I’m looking for them I do a google search for “mattress, city, state”, eliminate the ones that sell only major brands, and then do some extra research online or on the phone for the ones that have some promise. I go right through to the end of the google listings because there are often retailers or manufacturers that don’t have an online presence.
Post #2 here has the better options and possibilities I’m aware of in the greater NYC area. there is also a more categorized list with more detailed descriptions of some of them in post #7 here.
The same post also includes an optional step of online manufacturers you could consider … some of which make mattresses similar to the design you are mentioning.
A few examples of manufacturers who make multiple layer mattresses where any layer can be exchanged include …
https://www.foamsweetfoam.com/
Phoenix