I read that you re having problems with your back, i would like to suggest that you research into maybe getting an orthopedic bed mattress. It did wonders for me. The one i am using has like a thick foam padding on top that it is stiff enough for me not to sink in when sleeping. But it has grouped springs and would still give a nice bounce and soft springy recound. Only problem i think for me. Which is a very minor one i should say, is that the mattress is like maybe 10 inches thick. Or more.