I lost all of my good lookers before I even got on my trip. PS front tires must be original tread , no retreads alowed. Run the motors hot, check the brakes under stress, a std tranny needs to be able to downshift as emergency brakes, and double clutching is typical. Remember this is a medium to big size truck and will drive like one. Mine has a nose, flat fronts are good, but rear engines don't have a rear cargo door.
Air brakes are great with any wieght.
Hyd brakes are ok. They tend to get hotter more often. The older regs alowed the companies to use them longer. Modern buses last about 7-10 years, safety regs get them off the road. I bought a international 35' with a new front end, radiator, clutch and brakes with 130,000 miles for the same price I would pay withoiut those items.