I had a 68 C10 that was originally the same as what yours is. I had mine painted all blue, a light to medium blue almost sky color, it looked great painted like that. Also the holes you have to fill what about the "B" word? I don't like doing that but a little bit of bondo shouldn't hurt too much.
And the flames don't really look good on that truck, its not really that type of vehicle but can be a great sleeper.
Good luck with the truck and post some pictures if you can.