In this prank, the Jackass Crew will be tricked inot drinking a bit of ipecac (or willfully take it if knowing) before getting on a ride that will go up and down in a circular motion. While in the ride, the Crew will be shooting nerf guns (or any projectile in intrest) at people who are their targets, and thats when the magic begins.
Ok, so all you need is some paintball guns, some marshmallows, some fishing line and someone that is an unnaturally heavy sleeper. Since you guys got money, attach the paintball guns to individual stands aimed at the targets crotch or stomach. You take the fishing line, loop one end and that end gets attached to fingers,toes, wrists, ankles..etc. The other end of the string is attached to the gun(s) trigger via a simple pulley setup. The guns should not be able to be knocked over or moved off...
To prepare for the prank eat some dairy products or beans. Anything that will make you fart. Invite over a group of friends to have some drinks. Have someone be the designated camrea man.