Hi jethrodesign,
The first place I would start 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 know how and why to avoid the worst ones.
You can also see my thoughts about buying a mattress/topper combination in post #2 here and unless you can test the combination in person (in which case it can be a good option if there are no lower quality materials in the mattress) then it’s usually a more effective strategy to look for a mattress that already has the latex inside it that you would otherwise be adding as a topper.
Some of the better innerspring/latex hybrid options I’m aware of are listed in post #2 here.
It may also be worth considering a latex/polyfoam hybrid and some of the better latex and latex/polyfoam hybrid options I’m aware of that are also in lower budget ranges are listed in posts #3 and #4 here.
I’m not sure where you are in Southern California but if you are in the Los Angeles region then the better options and possibilities I’m aware of are listed in post #2 here and the list for the San Diego area is in post #2 here.
Phoenix