Hi tiredgal,
Just in case you are looking at a different list … the Los Angeles list is in post #2 here.
I just did a quick scan and only 3 of them (Foam Sweet Foam, Electropedic, and The Clean Bedroom) focus mainly on latex and would be worth excluding if you wanted to avoid latex (and The Clean Bedroom has some innerspring / natural fiber mattresses although these are in a higher budget range). All of the rest would have either regular innerspring or memory foam mattresses that don’t have any latex.
Just in case you haven’t read it yet … I would make sure you’ve read the tutorial post here which has all the basic information, steps, and guidelines that can help you make the best choices.
There is also more in post #2 here about the factors that can affect sleeping temperature that may be helpful in helping you identify materials and components that may sleep cooler.
Phoenix