i wanna to know if there have support for back and comfortable sleep, too.
A futon will kill your back. You need a sofa bed that has the option to order a better mattress inside. Klaussner Furniture offers 5 different mattresses for inside their sofa beds. You will pay a little bit more, but you will have it for a long time, and the comfort and stability you are looking for is there. I suggest the air mattress or the memory foam. They are both awesome.
