The only downside to going with a box truck is that it's tough to find one with a 30+ foot box to give you all the length. A DT466 or C-series Cummins is certainly more easily attained in one though. On the other hand, you can often get the boxes for scrap value. How about a pair of sea cans stacked on the back?
I don't mean replace the whole body. Leave the drivers area and a few seats, then transition to the box. It would give you the added height to put bunks, shower, etc. The challenged like me, that would never do a roof raise, would be able to get height, roll up door, smooth sides. I'm just throwing it out there for discussion. I know some might not like it.
A couple of other reasons I am bringing this up. Boxes can sometimes be found for really cheap. Buses are usually cheaper than trucks. Put the two together.
I was directing that at the guys that said to just get a box truck and forget about the bus. The issue there is you lose space.
Could be done - seems like a lot of work to keep from skinnin' the windows tho'.
I saw one a coupla weeks ago on the freeway that made me do a double take - guy cut off the back half of the bus and added a roll back and was carrying a pickup truck on it ... it was going the other way and when I first glanced over at it it looked like a shorty passing a tow truck.