You have a nice looking truck, you are further along than I am on the 5 ton camper project.  I have A 1990 M923A2 that I have been working on .  So far I have done some injector pump adjustments and exhaust improvements.  I have added a pyrometer to keep tabs on the exhaust temperatures and i'm in the middle of doing some air filter housing modifications.  In the cab I have an air ride seat for the driver and a 24 volt stereo .  Until I can build a camper for it I will use my Pine Mountain 800 in the bed.  Only problem is I need to build a lift system to get it in and out of the bed.