Hi nicole,
I switched your post to a separate topic to help me keep track of things a little more easily 
The first place I would start is the mattress shopping “tutorial” in post #1 here which includes all the basic information and steps that can help you find the best possible choices (and avoid the worst ones including most of the major brands). It will help you avoid “brand” shopping and focus more instead on the materials and components inside a mattress regardless of the brand label that is on the mattress.
Unfortunately there are not any Underground Mattress members close to us in Charlotte, NC and I don’t feel comfortable buying a mattress on the internet without testing it first. Any recommendations you have would be very appreciated!
Some of the better options and possibilities I’m aware of in the Charlotte, NC area are listed in post #2 here.
Phoenix