Hi mike7,
I agree with wavycat and you could do much better for a mattress with 12" of latex.
I would also take online reviews with a big grain of salt … most people who write reviews have little knowledge about mattresses (or what they have purchased). You can read more about reviews in post #13 here. I haven’t seen a legitimate poor review for SleepEz. There are always a small minority of customers who have difficulty finding their ideal layering with any component mattress (or any mattress for that matter) but that has nothing to do with the quality of the mattress or their service and it also doesn’t reflect the fact that the large majority of their customers are happy with the layering they end up with and are happy that they had the chance to fine tune their mattress after their purchase when it was necessary.
I think you would do well to talk with some of the manufacturers you are mentioning so you can get more accurate and meaningful information about their mattresses. In the case of Fobeds and SleepEz you will get more meaningful information about their mattress in a phone conversation directly with them than you would from spending many hours reading reviews.
As I mentioned in an earlier reply I wouldn’t pay too much attention to the gel in talalay GL latex because Talalay is already the most breathable of all the foam materials and you may be thinking it’s more important or effective than it is. You can read a little more about the many factors that can affect the temperature of a mattress (besides just the type of foam used) in post #2 here.
There are several places you may be able to order a PLB mattress online including http://www.themattressexpert.com/pure-latexbliss.html and it may be worth talking to https://www.mattresses.net/ as well who are also PLB dealers.
Overall though … I would focus on following the steps in post #1 here one step at a time and this can help you bypass all the conflicting and in many cases misleading information that is so common in the industry and only adds to the confusion and “information overwhelm” of mattress shopping
Phoenix