I have tried several... foam, memory foam, etc..., and when you need a fairly thin mattress to keep headroom intact, and enough density to not have your hips sore from sinking onto the platform, I have found by far the best is a pure latex mattress. They can be custom cut to your spec, they don't absorb moisture and are anti microbial... and come in 3 different densities (firmness). a bit pricy, but I value waking up feeling good... so I think it is worth it.., much better than the best foam... I'm over 250 and my wife is half of that and we both like the latex a lot more than anything else...
I know Bozeman mattress mill makes custom versions, i can vouch for their quality.... I sleep on it at home and in my expedition vehicle
I'm sure there are other makers around the country...
https://www.mattressmill.com