Hi BillC,
The better options that I’m aware of that are within reasonable driving distance of Portsmouth, NH are listed in post #2 here including some options around the Portland, ME area.
I thought I would spend a few hours this morning to see if any of the retailers that are closer to you would be worth considering as well (since I didn’t have a list in the Portsmouth, NH area) and list the brands they carried that I would consider on a “mattress by mattress” basis. I looked at about 15 or so different retailers (and one manufacturer) and the ones that I would most seriously consider are …
http://www.portlandmattressmakers.com/ or http://www.boatmattress.com/ Factory direct manufacturer in Portland, Windham, ME and Portsmouth, NH. They make a wide range of innerspring, memory foam, latex, and hybrid mattresses and have some good quality and value available. They would be well worth considering.
http://www.thecleanbedroom.com/ Kittery, ME. Carries Naturepedic, Natura, Royal-pedic, Greensleep, Savvy Rest, SleepTek brands. These all use high quality materials but also have premium prices as well (lower value) compared to many other mattresses that use similar quality materials and sell for significantly less. They would be a good place to test various latex options. (NOTE ADDED June, 2016 … The Clean Bedroom is now closed so I am keeping their listing on the list for the time being just for reference)
http://www.petesbargainbasement.com/ Dover, NH. Carry Therapedic made by MattressMaker (in Brockton). Carries the basic one and two sided innersprings and will disclose foam densities.
http://www.hubbingtons.com/ Hampton, Barrington, NH. Switched their line and currently sells Kingsdown (which I would avoid) and Pure Talalay Bliss which are a line Talalay latex mattresses that use good quality materials.
http://www.jandmfurniture.com/ Somersworth, Raymond, NH. Carries Therapedic memory foam, gel foam, and traditional innersprings. Told me they would call the factory for foam specs if they didn’t have them.
http://mattressdepotma.com/ Salisbury, MA Talked with Al here and he carries Therapedic and Gold Bond. We had a long conversation and he understands the importance of knowing the density and quality of the materials in a mattress.
Outside of the options that are in the other list I linked … these are the ones that are more local that I would be more focused on.
Hope this helps.
Phoenix