Hi Cyd,
the first place to start is post #1 here which has all the basic information, steps, and guidelines you will need to make the best possible choices. As you will see … a mattress is only as good as its construction and the quality or the materials inside it so shopping by brand is among the worst ways to choose a mattress. having said that … there are many smaller independent brands across the country that either sell factory direct or through better sleep shops that tend to use higher quality materials and have better value than the major brands and most of the mainstream industry.
A forum search on Habitat (you can just click this) will bring up many comments and feedback about them but in general they are not in the “best value” group as some of the other online options you have available to you IMO (which have a link in the “read first” post). To search the forum you just click the “search forum” tab just under the main menu (not the “search main site” window which doesn’t search the forum), change the “find posts from” setting to “any date” (unless you only want to search posts for the last year), enter your search words, and click the search button.
Post #2 here also has more information and links which can help you answer the question “how safe is safe enough for me?” but this a difficult topic with no clear answers (in spite of what many people would have you believe) and for those who are more inclined towards natural materials then some combination that includes latex and/or innersprings and/or natural fibers is usually the best choice.
Many of your basic questions are answered in the “read first” link but if you have specific questions that aren’t answered there then feel free to post them here.
I would also make sure that you include some local testing in your research and once you get to step 3 if you let me know your city or zip I’d be happy to let you know of any of the better options I’m aware of in your area.
Phoenix