greddy all the way....you can up the boost to 7-8 if you have the i/c kit and some tuning. A greddy kit @ 7-8 pounds will blow away the JRSC @ 6. Either way, it will be a awesome setup with that GSR swap in there...best of luck to you. If you decide to go greddy i can get the turbo/ic kits pretty cheap brand new. Hit me up.