I sure dont want to rain on your parade here and the Deuce is a great truck WITH KNOWN LIMITATIONS! Speed, increase tire size will hurt the trucks already limited ability to climb hill at any kind of highway speed, and its already very limited with stock tires. You are going to have a LOT of insulating to do in and under the cab to make it livable without ear plugs all the time. I generally always run Deuces at 2200 RPM on the highway that comes to about 52 mph with stock tires if there is a hill you can cut that in half. I would not personally mess with the fuel you are potentially opening up a big can of worms and your complicating things for your self! In cab comfort, everything in the Deuce is for function there is NO in cab creature comforts unless you add them.
A deuce was my second military truck and I have owned a few of them, great trucks but in you case I think your pushing things a bit, If I were in your shoes I would be looking at a 939 series 5 ton, they are already setup in much better fashion to do what your looking to do and with and automatic anybody can drive it, way better power, much more accommodating inside and they can climb a hill at a much better speed than a deuce can. Pricewise your going to be about the same cost. The 5 ton is higher cost initially but after you do all the things to make the Deuce livable your going to be at or exceed the 5 ton initial cost. There is ONLY 1 down side to the 5 ton and that is it wont get the fuel economy of the Deuce, in virtually every other way its a better choice!