I don't think I would want a laptop that had been banged around for years by students, but it you got to boot them up first it might be a deal. The displays, hinges and keyboards may be damaged, the batteries may not hold a charge, do you get a battery charger with it?
Finding an OS would be easy. Students get a pretty good discount. My niece in college got me the full box set of Panther new for $85 just after it was released. Comes in handy, too. The full box set has X11, but the restore discs with my eMac didn't.
Worker is right, better buy two or three to be sure you have enough parts. The superdrive to replace the stock cd rom sure won't be cheap, either.
It would have made a lot more sense to have a lottery-type drawing of names from a 'hat' seeing how many people there were.