I am looking for ~6" latex? mattress or mattress topper. I bought my current one in 2002, and now my wife and I are developing backaches. We bought it locally from a local maker, no longer in business. It rests on a hardwood base about 16" high, which in turn is on a conventional cast iron bed frame with slats that will hold a Sherman Tank. When we first bought it, it was advertised as being like "Sleeping on a very comfortable marble slab" and that is a pretty accurate description. We've been very happy with this setup for more than two decades, but now it's time to part ways.

I just bought and have returned a Plank Firm Luxe because I erroneously thought I could sit on the edge of the bed safely to dress, etc. (I'm disabled.) I slid right off so no joy there. Clearly I just need to replace my old latex solution. May I seek the wisdom of the internet as to where I can purchase such an item?

I am 6 foot 370 lbs. and my wife is 5 foot 4" and 120 lbs. FWIW

I am going to get a memory foam mattress topper as my mattress. I want something relatively thin because my van is small. I was thinking of getting a 3 or 4 inch one but I'm worried it would be uncomfortable (the topper is going to be the whole mattress, I won't have anything underneath). For people that are using memory foam toppers as mattresses, what thickness would you recommend?