.480 lift is kinda moderate IMO. I would go with something like a .510 lift with a nice duration. For the sound you want if you decide to go with the TH350 you'll need a stall. If you go with anything bigger than a stock cam i would suggest z28 valve springs. As far as matching everything holley makes a systemax kit but comes with an RV cam and may not give you the lope your looking for. If i was you i would go with .510 lift cam, have the valves and seat ground, victor jr intake, holley 750 double pump carb, valve springs to handle the cam, new push rods, and headers. Dont worry so much about the factory HEI its a good ignition and is easy to tune, dont need anything crazy unless the rest of the motor is crazy.