IMHO, only if you have really monster hills and a tired motor would I consider this.
These busses are made to haul a passel of kids, books, band equipment, etc, and THEN the engineers double it and add another 40% as lawyer-repellent. So these things are already stiff. Take out the seats, interior, etc, and haul rice cakes instead of three football teams and you're gonna have some ride issues.
Sincere suggestion: do a road trip empty before you do anything else. Just drive it and listen to the voices in yer butt. I say this because I was totally gung-ho to cram a DT-530 making 350 hp coupled to a 6 speed into my bus... and then I drove it 5000 miles. NOW i get it. NOW I'm on the same wave-length of the designers. Stock is simply fine.
Maybe whatever demon is telling you "go light"'can be exorcised by a simple road trip.