RE: Air Mattress or Cot?
If you get one of the large cots that Slumberjack or Cabela's makes, you can store gear underneath it, and they are very comfortable. I used air mattesses for years, till I tried a cot. I think a cot is a much better way to go, more comfortable for a better night's sleep and you can store boots, etc, under it. I do put an extra blanket or even a foamy under my bag on the cot, and it stays very warm that way.
I'd buy the biggest, most heavy duty cot you can find. You won't be sorry you have it.