Hi lipoo,
Some of the better options in the Memphis area that I’m aware of are in the second part of post #2 here.
Some thoughts about Luxepedic are in post #9 here.
If you are looking to purchase a memory foam mattress online … then post #12 here has some good options.
If you are not necessarily looking for memory foam but are looking to purchase online … then post #21 here has a list of the manufacturing members of the site that specialize in providing the kind of help and guidance on the phone that people may need in making the best possible choice and have great quality and value.
I would tend to look locally first though because personal testing on a mattress is less risky and can be more “accurate” than an online purchase but the online outlets are always available if a local purchase carries enough of a “premium” that the extra “risk” of an online purchase is well worth considering.
Phoenix