We got our from Burlington and it's in great condition as far as chassis, tires, etc. The bus garage guy hid a coolant leak from us, though, and we had to do a rebuild of the engine. That being said, if you make sure to DEMAND the paperwork on the bus maintenance history before buying, they have some pretty nice condition buses. I'd stay away from the mountains and coast due to rust, but even they don't have much rust compared to other states. I visited a few garages in the Piedmont and they were all decent.
My build thread:http://www.skoolie.net/forums/f11/build-thread-for-haulin-oats-and-goats-11237.html#post113500
A gal, a guy, three cats, two dogs, one rabbit, and one goat, traveling the country together.