steelsoldiers.com is a great resource. I owned an M35A3. 2.5 ton off road truck for several years. It would haul the largest truck camper as if it was not there, the truck had a 10,000lb on-road payload. There have been several guys that have done this, it requires removing the jacks and you can build boxes under the sides for additional storage if you had a truck with a drop-side bed.
Downsides? Most military trucks have limited speeds, my truck topped out at about 50mph. No a/c and like nearly every deuce I ever drove, it leaked rain on your feet. My truck had a nice heater, air-assist power steering and an air ride drivers seat. If you like your passenger, you'll buy another air ride seat. My truck got 10-13mpg on the highway. It will be tall, mind your height.
Upside? 6x6 gets you darn near anyplace. You can easily ford 4 feet of water. It will be cool. My truck used commercial truck parts and oil changes were five gallons a wack. Nearly everything was available at NAPA.
