Re: driveshaft to equip compatability
well that depends... i'm not an expert on bus parts, but i know a thing or two about drivelines in general.
see the thing that you need to be worrying about more is driveshaft length. although i have had friends make driveshafts in their own garages, it's not a good idea unless you really know what you're doing. even if you can weld on the yokes perfectly straight, you'd have to balance it.
as far as splines not being compatible, it can be a DIY job. the pinion yoke (rear end) should use a standard u-joint size which hopefully would match up to the driveshaft you'll be using. as far as the transmission goes, it's the same situation. in any case the yokes being the same size won't really be the hard part as i'm sure you can find replacement yokes for the tranny and diff to fit your u-joint size if need be. if anything doesn't match up it's just a matter of finding out what would be cheaper to do.
hope that helped a little
unfortunately i fell off the bus. and now i'm not even near the darn road! ;) ;)