After much research, I bought a latex mattress online from SleepEZ (an American family business based in Arizona).
#1 advice that was given to me: Do not buy a big-name mattress (most begin with "S"). These used to be fine American companies, but their mattresses are now made in China and are cheap in every way except price.
Foam mattresses are great for anyone with aches and pains, as they provide excellent pressure relief.
Latex foam is completely different from
memory foam. Latex is a natural rubber product; memory foam is made mostly from petrochemicals. Memory foam molds to your body, providing pressure relief, but you will slowly sink down into it throughout the night; some people like this, some don't. I felt like I was stuck in concrete and had a hard time turning over. Latex also provides excellent pressure relief, but it also has "bounce" so you don't sink in; it's more like floating while being gently supported. And I don't wake myself up just trying to turn over.
An alternative to an all-foam mattress, which are expensive (I did this for the guest room and it turned out great). Buy a no-frills, no-name, very firm, American-made, flippable inner-spring mattress. (No "luxury top"; those are stuffed with cheap poly-fluff which breaks down quickly.) Your local mattress store will probably carry this mattress, but will not want to sell it to you.
Then buy a 2-3 inch topper, either latex or memory foam, depending on which you like best.
Watch out for "cheap Chinese memory foam." A quality high-density memory foam or latex foam topper should sell for around $300 (queen). A quality foam bed will last a lifetime.
SleepEZ sells toppers as well as complete foam mattresses, and they are high quality
Sleep EZ Organic & Natural Latex Mattresses - Family Owned Since 1976
For memory foam, check out
Mattress Toppers by Brooklyn Bedding - Comfortable & Affordable
Do a little research online before you buy. Mattress Underground is a good forum, highly recommended.
The Mattress Underground - Your best source for information on mattress brands, materials, and choices
Good luck!