Hi terminaldawn,
Post #21 here includes the members of this site who specialize in online purchases. There is a wide range of different styles, types, and budget ranges among the list but for many (and sometimes different) reasons they are all IMO among the best value in the country and are good reference points for a local purchase.
Plushbeds has good quality mattresses and better than average value but is not in the same “value range” as the outlets in the post I listed. A forum search on Plushbeds (you can just click the link) will bring up more comments and information about them.
The actual construction of a mattress is much more accurate if it’s based on local testing with the help of a person who knows all the details of the specific mattresses they sell rather than “theory at a distance”. Even for an online purchase, it’s always better to use the help and suggestions of the specific manufacturer because they know all the smaller details of their mattresses that can sometimes have a big effect on how the mattress may feel and perform for a particular person. They all have a large customer base which gives them more insight into how each of their mattresses may work for people that are similar in height/weight/body shape and sleeping positions based on “averages” that work for most people.
There are some general guidelines for height/weight/body shape in this article however and some guidelines for different sleeping positions here. These are all based on averages and are meant to give people an idea about how ILD’s and layer thickness can work together in how a mattress interacts with different people. There is also some information here about “putting the layers together” (and more detailed information in some of the sub pages in the same section) that may also help give some understanding about how different types of layering and some of the other components can affect the feel and performance of a mattress.
In general though … it’s better and more effective to gather enough information that you have a starting point and so you you can ask better questions and make more sense of the answers than to try to design a mattress based on either personal or mattress specs or what I call “theory at a distance” which is more about “averages” and don’t include the many variables that can apply them to specific people.
Good luck in your research and I hope you let us know how it goes … or of course post any questions you may have along the way.
Phoenix