What about 1969 code 63 champagne or code 65 olympic gold. I think the olympic gold would look really good. Interior must be black, correct?

I vote black and gold if you're going for that old ZL-1 look. You're definitely not going to see another one at a show 99.9% of the time, and you know it looks good already since the original prototype. Finding the right gold is the key, I agree, but there are so many different colors these days you should be able to find something close. House of Kolor is still in business and have a ton of different colors to choose from:
http://www.houseofkolor.com/kolors/?ref=homepage

There was a local guy here back in the early to mid 1990's that had a black Z/28 with red stripes. I doubt it came from the factory like that. I don't know if the black was even the original factory color as I never got to view the trim tag. I did think it looked very nice though. That being said, my vote would be gold stripes with the black exterior. It would remind me of Smokey Yunick's Camaros with the black and gold colors.

Either looks good but I do like the black & gold combo. You might try looking at Hurst Olds cars from the late '60 and into the '70s to see what color gold they used.

Another unique look would be black with gold lace stripes. No matter what decision you make if you don't like it five years from now you could repaint them. Come back in five years when you repaint and get different opinions from the same people.

http://www.nickeyperformance.com/wp-...ow-car-003.jpg

http://st.hotrod.com/uploads/sites/2...river-side.jpg

http://st.hotrod.com/uploads/sites/2...nd%7C596%3A372

black and gold go good together imo...