The best bang for your bunk when it comes to rebuilding that i've found has been from this website click
They sell nippon pistons and rings and acl bearing at amazing prices. These are what i use when i rebuild these motors. Never had an issue yet. I believe i got a set of pistons with wrist pins, rings, main, and rod bearings all for $110. Now when it comes to gasket sets I'd go to your local auto parts store and buy felpro gaskets. Get a head gasket set and a "conversion" set (thats what there calling the lower gasket set now apparently). I like to run felpro head gaskets as they are a good reliable brand but there not EXTREME so that if there were an internal error as far as boost wise the head gasket would blow before there was major damage done to the motor. As far as a forged crank i wouldn't bother with it unless your planning on running in excess of 600-700 whp. I believe shepherd ran 9s or 8s with a stock crank.