Very funny ideas though why is the second one called the preppy ending since it didn't have anything to do with the preppies. Maybe instead of bribing Crabblesnitch, which would seem unlikely to work anyway, Jimmy bribes Derby and in turn Derby gets his father to go over Crabblesnitch's head and convince the school board to reinstate Jimmy.
Here, let me try one:
JOCK ENDING
Jimmy gets reinstated at Bullworth and makes up with the jocks but is a permanent enemy of the nerds. Also Burton apologizes to Jimmy and keeps his job, but Zoe is not reinstated. 100% respect from the jocks and bullies. 50% respect from the preppies and greasers. 0% respect from the nerds and townies.
How to get? Only complete gym classes, unlock the dunce cap, and defeat Gary.