How about leaving the silver(?) as a side stripe, and run the black forward along the same line just below the bedrails? (painting the cab and upper portion of the doors) Follow the line forward until you hit the fender, make it a straight line with the upper grille surround.
That might be ugly too, but if I'm not mistaken, that's similar to what the factory did. I personally like the two tone, if the colors are good, and black/silver do look good together.
It takes a good eye to come up with something other than black. (especially to make two tone look good) In my opinion, black is way overdone in vehicles, at least when people do it themselves. I appreciate a nice black 4th gen Firebird or 80's Monte SS as much as the next person, but on a resto or repaint, it's just cliche.