I looked at about twenty buses before finding a high-clearance model.
It cost more than I'd hoped, but it was the perfect bus: high ceiling, under-chassis bays, full air brakes, DT466 engine, and front & rear air conditioning. The only things I don't like are the automatic transmission and the Dayton wheels. I'm not a little guy, but not that tall...just short of 6', my wife is 5'8". One way I maximise the available height is by most of the floor insulation being sprayed-on foam underneath the bus.
I would never even consider a raised roof...I'm not comfortable with surgery that major on structural parts. I would never even CONSIDER selling a raised-roof bus...the potential liability is staggering.