You'll need the complete subframe, engine, trans, cv axles, wiring harness, and PCM. Just buy the car so you'll have everything there.

Your best bet is to put an L67 in there. A supercharged 3800 will be a drop in deal. You just need to find a wrecked 00-05ss and get the motor out a Grand Prix GTP or Regal GS. Check out MotorSwap Brian Teel has built a very thorough database. They also make a CSC kit for the 3400. One guy in Florida is running it and he's had good results. You can get more help over at www.CNFCGP.com It's the Central Florida Chapter of ClubGrandPrix.