Hi Gresham,
You are certainly looking in a good direction and as you probably know Parklane is a member here which means that I think highly of them and they compete well with the best in the industry in terms of their quality, value, and service.
They are also transparent about the materials they use in their mattresses. Each of their mattresses have a description on their website (just click the description tab) which includes most of the information about what is inside them but they will also provide you with any information you need that isn’t included in the descriptions (see this article) if you ask them.
While they use good quality materials and components in all their mattresses … the most important part of the “value” of a mattress purchase is how well it matches your specific needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences). A mattress that is “perfect” for one person or even many other people may be completely unsuitable for someone else to sleep on because of differences in body type, sleeping positions, and preferences so careful and objective testing using the testing guidelines in the tutorial post is the best way to decide which mattress is best for you based on your own experience and on the parts of your personal value equation that are most important to you.
Phoenix