Depending on what scale you're looking for will determine what you can find. The '50-'53 seems to be most popular. there is a plastic kit of a '50, and there used to be a resin cast conversion to make it a '54. Not sure if it's still available.
Off subject, kinda, anybody looking for a '50 GMC 1/2 ton stake dicast might want to check Menards. They have a nice 1/18 scale die cast in red and green for around $19. There's also a '41 Chevy in 1/43 (opening hood and doors!) for $8.
