Bed Bath and Beyond has an Aerobed thin air mattress named PakMat wich is perfect for camping or backpacking which means it is small when deflated. You'd need 2 of them side by side to make a full size bed. Comes with a hand pump but a battery operated pump is cheap if you want power inflation.
Years ago we used an Aerobed 3-1/2" mattress topper on top of our Lance Truck Camper RV mattress as it was infinately adjustable by inflation level. It was fabulous but after 9 years of continous use and our Siberian Husky jumping up on it, finally got lots of holes in it and too many to patch. So, We replaced both it and the mattress with and Aerobed dual individual side control inflation with the built in air pump that runs off our inverter/s 110 AC. Wife is disabled and needs to vary the inflation on her side most nights.
Then we did the same thing for both our 5th wheels and it works great and is so comfortable. Never will go back to a regular mattress. In our Travel Trailer (now sold) we had a Coleman air mattress 60" X 74" and it also worked fine but did not have dual inflation so we put a 1-1/2" memory foam on top of it and it's perfect without having dual inflation. The Coleman has never leaked or developed any "bubbles" and definately was not uncomfortable.
The 3-1/2" Aerobed topper air mattress is what you want if it's still made or two PakMat's.
Another huge gain in the truck camper is that a normal mattress gets very cold thruout the entire time sitting on top of the cabover base in winter and takes all night to warm up and you are chilled all night. However, the air mattress just being air inside, warms in less than an hour from laying on it or simply preheat it with an electric thermosat mattress pad or electric blanket plugged in to an inverter. They only draw around 80-100 watts and just when they are actually heating. Bed's usually warm in about 15 minutes or 30 minutes in below zero outside temps. The built in thermostat won't call for any heating or very little after your body heat is laying on the mattress at night so it doesn't run down your batteries. We've used the heated mattress pad every night in the winter in the TC even in below zero temps in the U.P. of Michigan boondocking many times and never ran the batteries low while also having the RV furnace running all night. Some TC's are poorly insulated and that will make a difference in battery draw too. We love winter camping but not ever having a cold bed! My wife couldn't take it nor could/would I!