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.
The Interior is completely gutted and all pictures that I had were lost when my phone was run over by my garbage truck (short story but not relevant). But the bench was replaced by buckets from a 1967 barracuda the interior trim code is H5W so basically the seats arm rests and door skins were Pearl White and the headliner, dash, carpets, upper painted door door area, back area behind the seats were all black with the stainless mouldings, also the console is black. As for the stripe white was available although I am leaning towards having them painted on instead of stickers and also going pearl white stripes to match the seats. I saw a charger with mirror black paint and matte black stripes, I fully agree a slight difference in color from the main body looks awesome.