Sal,
Is that you in the avatar? That's how you should look when approaching someone for parts!
The reply will be, "OK mister, just take 'em! Don't hurt me!"
Just my 2 cents. Here's what I would do (Of course limited by the almighty $$$):
Bill boards are cool, uniquely 'Cuda! Digital gauges are neat but harder to read quickly vs analog. Auto Meter has a cool line of gauges that have a black background, blue digits, red/orange needles. Some people are popping aftermarket gauges right into the pods of non-rallye dash panels and it looks cool and might be cheaper than finding a rallye dash panel. Black leather is cool, gotta have a '71 Go Wing, gull wing style. Don't forget the '71 'Cuda only side gills on the front fenders. Looking at the posted pictures, yellow looks pretty nice. Could make it unique by making it triple black,Triple White, White with with white bilboards, triple red, etc... Rallye hood is nice but a shaker is cool There are some fiberglass reproductions that you might be able to make it work. Some people put little lights in the openings of thier rallye hood openings. A little ricey but it looks cool at night!
Hmmmm...rims and ride height......hmmmmmm. Stock rallyes are nice if you want to go mild. If you want to go wild, got to go for monster meats, 50 series on Cragers/Weld Racing/American Racing rims, 15s all around, 10 inch wide in back. Nothing says "I'm gonna kick your butt!" at a redlight like a big set of rear tires (Gotta lift that rear end of course!) and a loud exhaust!