Hi Len S,
There are some excellent options in the Los Angeles area including one of the members here which I would suggest would be well worth including in your research. They are listed in post #2 here.
While I certainly love the idea of making a purchase online where you can choose your own layers … my personal preference would always lean towards a mattress that I could test personally and that could also be customized to my preferences … even if there was a premium involved in terms of price. If there were no local manufacturers within reasonable driving distance or local choices were much more expensive for an equivalent mattress (the "premium was too high and I was willing to take on the additional risk in exchange for the savings), then I would lean towards an online manufacturer who was knowledgeable and offered exchanges of the mattress or layers at a reasonable cost.
Side stomach sleeping combinations are the most difficult of all combinations sleeping positions because the needs of stomach sleeping (as thin and firm on top as possible with firmer support layers) are the opposite of side sleeping (thicker ans softer on top to accommodate the more curvy side sleeping profile) In these cases I would choose the thinnest and firmest layering I could that would adequately relieve pressure on my side to help accomodate my stomach sleeping. In the case of the PLB, the Beautiful has 3" of 19 ILD over 2" of 24 ILD which would likey be on the soft side for you. This would mean I would choose the Nutrition over the Beautiful and the Nature over the Nutrition if all of them relieved pressure on my side. I would also consider firmer latex on the top layers (which the PLB doesn’t offer) if I knew that would also relieve my side sleeping pressure well. Zoning with the middle section firmer than the areas under the shoulder and legs would also be an option worth considering.
While nothing but your own personal testing (especially with the help of someone who has the knowledge and experience to help you in person and can see you lie on each mattress) can answer “is this too soft for me?” for certain, I would tend to avoid a mattress that was quite so soft with your height and weight and combination sleeping unless it was the only pressure relieving option that worked and even then I would be hesitant (I think alignment/support is more important than pressure relief which can be adjusted with a topper if you can’t adjust to it).
If you did decide to go with SleepEz … then it’s likely with your side sleeping that you may need the 10,000 but if your testing indicated that you could “get away” with a 2" top layer then I would go in that direction again for the benefit of your stomach sleeping.
Hope this helps … and you have some very good local choices.
Phoenix