a matress that will roll up and store

Hello,
I have designed and fabricated a miniature HD trailer capable of off road heavier duty usage. Only nine feet long, I will have floor space, benches etc. In the evening I want to place a mattress exactly three feet wide by 6+ long, and be able to store it by rolling it up and stow it under my bench during the day, allowing full usage of the interior with an external galley.
I will be using this camper before its finished completely, but need to get this mattress that won't bottom out when I am sleeping on the floor. I am 200+ pds. and the material needs to be rolled up into a 24" roll. The idea of maximum usage of a living space in my camper revolves around getting the correct mattress material, and I sure could use your help on this because there is absolutely nobody around with any experience at all in this matter.
Thanks in advance
Gene So
I have designed and fabricated a miniature HD trailer capable of off road heavier duty usage. Only nine feet long, I will have floor space, benches etc. In the evening I want to place a mattress exactly three feet wide by 6+ long, and be able to store it by rolling it up and stow it under my bench during the day, allowing full usage of the interior with an external galley.
I will be using this camper before its finished completely, but need to get this mattress that won't bottom out when I am sleeping on the floor. I am 200+ pds. and the material needs to be rolled up into a 24" roll. The idea of maximum usage of a living space in my camper revolves around getting the correct mattress material, and I sure could use your help on this because there is absolutely nobody around with any experience at all in this matter.
Thanks in advance
Gene So