I recently bought a new mattress, and almost lost my mind in the process with all the various options out there. I found this site to be immensely helpful.

http://www.themattressunderground.com/mattress-forum.html

I ended up purchasing an all latex mattress from a local manufacturer and ended up saving a lot of money in the end. I couldn't get over the "sinking" feeling that a memory foam mattress had. I also liked the idea of an "all natural" product and supporting a local manufacturer. The guy who runs the site seems to have contacts in the industry around the country, so if some one already hasn't asked you can post and he'll hopefully provide you a few local spots to start at.