Hi Jstempi,
I would tend to avoid getting involved in specifications (other than “quality specs” to help you make more meaningful comparisons), especially with local testing. Your body, good objective testing, and the help of a knowledgeable “sleep professional” will be your best guideline.
In general terms higher weights will tend to need firmer support layers and firmer and thicker comfort layers than lighter weights. You can also read more about different ways that can help accommodate weight differences in a couple in the first part of post #2 here … but knowledgeable manufacturers and retailers will already know and be able to help you with what you would otherwise need much more time to learn.
Los Angeles has some very good options available 
Phoenix