Hi Tracieknits,
You’ve probably seen these but just in case … the closest manufacturers to you are in post #2 here.
Post #4 here has some local retailers that may carry latex if you want to test it. You would need to make a few calls to find out for certain.
Latex is the most breathable of the foams so it can help with sleeping hot. Post #2 here from earlier today talks more about the many factors that are involved in temperature regulation.
With your higher weights it becomes particularly important to make sure that any mattress you purchase uses high quality foams in the comfort layer. I would be very cautions about using memory foam under 5 lbs because of durability issues (such as is used in the Tempur Weightless Supreme that uses 4 lb memory foam in the top layer). I would also want to know the type of material that was used in any mattress I purchased and its density and thickness if it was polyfoam or memory foam as well. Buying a mattress that uses unknown materials can be a recipe for foam softening much too quickly with heavier weights. From a durability standpoint … and assuming you like its feel and performance … latex would make a very good choice by itself or in combination with other materials because it is more durable (and breathable) than other types of foam and it doesn’t have the “motion restricting” feeling because it is a fast response foam with very high resilience. Thinner layers of memory foam “in the mix” would reduce the effect of foam softening and give you more of the feel you prefer as well.
The key is always to know what is in any mattress you purchase and not to take anything (such as quality and durability) for granted.
If you do like the feel and performance of the Weightless series … then it may also be a good idea to consider an online purchase from one of the manufacturers listed in post #12 here. One of them (Select Foam) has a line of mattresses that has been designed and tested to match the Tempurpedic mattresses and uses the same or better quality materials. Most of the others would probably have a good idea of which of their mattresses was the closest match to any of the Tempurpedic line as well.
Phoenix