Hi Gene,
Reply #2 here lists several independent manufacturers in the area.
OMF is a good manufacturer but unfortunately they only have 2 latex models and little way to customize them if they don’t work for an individual. The basic is a 32 ILD latex core quilted with an inch of polyfoam on both sides and so would be rather firm for most people and sleeping positions. The supreme is 1.5" of 19 ILD convoluted latex with an inch of polyfoam quilting in the comfort layer over the same core which means it would be very soft in the comfort layer since the convoluted latex would be the rough equivalent of 14 ILD or even less.
I have talked with them on several occasions including this morning (to the factory) and I suggested that with the rapidly increasing interest in latex (one of the fastest growing segments of the industry) they would do well to increase their latex selection and hopefully remove the 1" of polyfoam that they have as this would give people looking for latex a way to have more choices in both the comfort layers and the support core.
Fox mattress orange city location IMO would be by far the best way to go out of the two near you since they would have a greater selection of latex choices so you could find the layering that was best for you and they are a factory direct manufacturer with great service and value. The short drive would be well worth it. They are also a member here so you would be eligible for a 5% discount if you let them know that you are a consumer member of this site.
The actual thickness of a latex core that is suitable for an individual would depend on weight and preferences. Latex cores are normally 5.5" - 6" thick depending on the type of latex and the manufacturer and in the vast majority of cases this would be fine. The thickness of the comfort layer on top of this would vary with the individual. This would usually be in the range of 1" - 3" depending on the sleeping position and weight distribution. This means that the total latex in a mattress that was suitable for the vast majority would be between 6.5" (5.5" core + 1" comfort layer) to 9" (6" core and 3" comfort layer). Two sided mattresses would add the thickness of the comfort layer to both sides (as in the OMF).
Some people who are very light could easily use a thinner core (and likely a thinner/softer comfort layer) while those who are very heavy may use some additional thickness an/or firmness in the support core and the comfort layers. A latex mattress that is on a tension adjustable slatted base which acts as part of the active support system can use an even thinner core. OMF usually displays their latex mattresses on an innerspring which I personally don’t think is the best idea but it would also allow for a thinner support core.
Latex has a very high progressive compression rate (what is called support factor) and so can be successfully used in thinner support layers and thinner overall mattresses than other foams and types of mattresses.
Phoenix