Hi ritaelyn,
You’re most welcome! Subject to confirming that any retailer or manufacturer on the list is completely transparent ( see this article ) and to making sure that any mattress you are considering meets your specific criteria and the quality/value guidelines here … the some options or possibilities I’m aware of in and around Las Vegas are listed in post #2 here. Las Vegas Luxury Beds has Savvy Rest latex mattresses, and Kaylee’s Family Mattress might still carry Pure Talalay Bliss (you’ll need to phone them to find out).
I’m not aware of a weight capacity for this product with the luroy or lonset slats, but Ikea does have latex mattresses that the Brimnes is designed to hold. While the entire weight of the mattress is distributed over the slats and not concentrated on just two or three, I do share some concern with their slat construction and it would simply keep an eye on the amount of deflection the slats experience over time or if they delaminate or become concave, at which point you’d want to replace them with a new slat insert. Of course, you do have the option as you stated of cutting your own 1" x 4" slats and creating your own deck using flat pieces and that would work well, keeping to a space of no more than 3" between the slats.
Phoenix