Gordon,
Just my 2 cents for what they may be worth today. I'd be inclined to take Door #2, the one on the right side of the barn, if you have a choice. I see a slope rolling off to the left side of Door #1. It looks almost as if it starts within the door opening which may not be good for things under the bus. I'd also envision how you are going to get the bus back out of the barn, and turned around, not just look at how you will drive it in. The in part is easy, well in this case it will be. Other than that it does look like a very suitable building for storing a bus.
Happy Bus Hunting season is now open!