I picked up a late 80′s 40 foot GMC RTS (transit bus) for about $3,000. Recently rebuilt engine and transmission. The damn thing will outlive me.

I don’t know about using a school bus for this kind of application. They’re not really designed for the pulling power of the bigger ones. Mine has a DD6v92TA + Allison 3 speed. I put my car on a trailer behind it, and barely knew it was there. I had to keep checking for the shadow following me (mine’s 8.5′ wide. My car is about 6′ wide). Of course, you can’t just chop the back out to be a patio, being the engine is in the rear and all. I don’t mind the lack of engine noise when I’m driving though.