Hi ssh33,
The mattress shopping tutorial includes this link to a list of the business members here that sell online and many of them make latex mattresses and hybrids that use different types of latex, have different designs, features, and options and a wide range of different prices.
If you let me know your city or zip code I’d also be happy to let you know of any of the better options or possibilities I’m aware of in your area.
Several of the manufacturers on the list have split layers available in queen but others only make them available in king mainly because a king would use two twin XL layers which is a standard size while a split queen uses a non standard size for each side.
There are too many unknowns, variables, and individual preferences involved for anyone (including me) to be able to predict whether any mattress design would be a good match for you based on a formula, “theory at a distance” or specs (either yours or a mattress). When you can’t test a mattress in person then the best source of guidance is a more detailed conversation with a knowledgeable and experienced manufacturer or retailer that has your best interests at heart and who knows more about their mattresses than anyone else. They are in the best position to “talk you through” the options they have available that would have the highest odds of success (see mattress firmness/comfort levels in post #2 here). At your weight there is no inherent reason why a 3" latex comfort layer wouldn’t be “enough” for you but whether a mattress as a whole is a good match for you in terms of PPP always depends on the complete design of the mattress and how all the layers interact together, not just on a single layer.
I don’t have any personal experience with any of their mattresses and hopefully some of the members here that do will see your post and share their experiences but in the meantime a forum search on any of them (I would set the “find posts from” setting to "any time) will bring up more comments and feedback about most of them.
Phoenix