Hi nancy361,
First of all I would echo 70sleeper’s suggestion and I’m glad to see you’ve read the overviews. 
There are also some guidelines in post #10 here which may also be helpful (if nothing else they can help you avoid or eliminate most of the worst quality/value choices).
Before I considered an airbed I would also read this article.
Philadelphia is dominated by large chains such as Sleepys, Americas Mattress and others and quite frankly I wouldn’t walk through their front door even to test mattresses much less buy one. They just won’t provide you with the information you will need about the major brands they carry to make good choices or in some cases to even know the material you are sleeping on. Some of the better options or at least “possibilities” that I’m aware of in the Philadelphia area though are in post #4 here.
Hope this helps
Phoenix