Hi kmfischer,
Just in case you haven’t read it yet … the first place I would start your research is the tutorial post here which has all the basic information, steps, and guidelines that you will need to make the best possible choices … and learn how to avoid the worst ones.
As Jefmoody mentioned … Dreamfoam Bedding is one of the members here which means that I think very highly of them and they compete well with the best in the industry in terms of quality, value, and service. They are open and transparent about the quality of the materials they use inside their mattresses and will also give you good guidance when you talk with them on the phone to help you decide which of the many options they make may be the most suitable choice for you.
Post #3 here and the posts it links to also have more information that will be helpful if you are in higher weight ranges which will generally require more durable materials and firmer support and comfort layers than others that are in lower weight ranges.
Phoenix