I was thinking more about your question about mattresses, Rockinamini.
I have a lot of my patients asking me what kind of bed mattress is good for them. Since I am not in that line of business, but am in the business of musculoskeletal injuries--I always give them the advice of trying it out in the store and also making sure there is a 30 day return policy as I said in the previous post.
However, you may also consider other things to keep you comfortable. Such as using a pillow between your legs when sleeping on your side to keep your hips and knees level. This makes it more comfortable and less strain on your sacro-illiac joints.
Also, if sleeping on your back stacking a few pillows under your legs is good to do if you need that low back support. I don't recommend to do that forever, but sometimes it feels better to have a few pillows under you on days that you might need it.
Hope that helps!