Need bed ideas

My current bed is a full size, 10+ years old, had adjustable head and feet but no longer works, so I think it's time for a new. I'm just having a really hard time figuring out what to get. Should I go with memory foam or air mattress? Or should I just get a spring mattress with a foam or air topper? What size mattress should I go with, twin or another full? I like the extra room of the full, but that means a lot more work for my PCAs having to reach and pull me across the bed. Are hospital beds the same size as a twin mattress? A little about me. I'm a C5-6, weigh about 170 and I'm 6'4. I'm unable to turn myself. I'd like a bed with adjustable head and feet and also elevates. My PCAs give me range of motion and also help me get dressed in bed, so a bed that elevates would help their back. Any quads in a similar situation have any recommendations? It would be nice to find someplace that I could buy and try out a mattress for a while and return it if I don't like it. I had bought a new bed, full size tempur pedic last memorial day, but I cancelled the order because I wasn't sure. The place I got it, Becker, didn't have a return policy, only an exchange policy for something equal or greater value.

Thanks

Need bed ideas