Hi nostigex,
The closest lists to you are the Portsmouth area list in post #2 here and the Boston region list in post #2 here and the list for the Merrimack area in post #4 here.
Other than these (and even with these) I would do some preliminary research on the phone first (along the lines of this article) to make sure you would be able to find out the specifics of what is in any mattress you are interested in or you may find yourself in the position of liking how a mattress feels in terms of PPP but with no way to know the quality or durability of the mattress or make meaningful comparisons with other mattresses.
Depending on the licensee that makes them… Therapedic is usually more open and transparent with their foam specs than many other larger manufacturers (see the list of the top 16 manufacturers here) and can have better than average value but it’s always important to make sure that any retailer that carries them will take the time to get the information you need to make an informed choice instead of looking at you like you are crazy for wanting to know more about the quality of the materials in a mattress.
At the very least any retailer you deal with should be willing and able to find out (from the factory if necessary) the thickness of all the foam layers in a mattress, the density of any polyfoam or memory foam, and the type and blend of any latex. They should also be knowledgeable enough to be able to tell you what they mean but if they don’t then you can always post them here and I’d be happy to make some comments or help you identify any weak links in a mattress you are considering.
Phoenix