Color thoughts 68 Barracuda

I don’t think that you can go wrong with either color, but I prefer the original color on cars, even cars that have had visual and/or performance modifications, as a way of connecting the new with the old.
Can you post a shot of the interior?
I don’t know that I have ever seen a black / white I interior.
For the side stripe, and I like those also, I would match that to the color of the side strip that was available on that body color back in the day. If I was going to do a stripe color different from OE I would strongly consider doing a tint of the body color. Enough tint to see that it is there, but matching to look like part of the exterior not necessarily part of the interior.