I've done the head, cam, and fuel injection to my Kammback. Very noticeable improvement after the cam and head swap, then several years later I added the GM TBI, which to me greatly improved the acceleration and driveability. Not sure the acceleration improvements would have been possible without the cam and head swap. The throttle body kit came from Performance Fuel Injection Systems, they have their own web site and also sell on eBay. It's a nice kit.
Good luck!