Hi AMG_Roadster,
I think your thinking is “accurate” and you have outlined the pros and cons of your choices very well.
You can see some of the factors involved in sleeping temperature besides just the foam in the mattress in post #2 here. I don’t think most people would have a heat issue with either of your choices unless they were very sensitive in which case latex may have an edge (although some of the other factors may play just as big a role as well).
You are certainly looking at some very good final choices and I would base my decision on your own personal testing, on the conversations you have with each manufacturer, as well as your personal preferences between the “feel” of memory foam vs latex.
Phoenix