Your link doesn't want to work for me so I couldn't see your car. But I say do what you like - especially if its alreadu not stock and do not plan to return it to stock condition.
I just went through the same thing with my 68 (originally a 6 cyl car) so I wasn't worried about "wrecking" a rare car. I went with a base-coat/clear-coat pearl red with a white hockey stripe, 383 fender emblems, and a cowl hood - the way I like it! I am happy with the results and people at cruise-ins seem to like it too.
I will say that I've never been a big fan of gray (kind of bland IMO), but I don't know what you have in mind exactly. I've seen some really awesome looking deep pearl blue's and deep metalic greens that really look nice too if you want to avoid red and other common colors. Whatever you decide, definately do the car the way you want it - you'll be happier in the long run that way.