Another option, while certainly not cheaper, would be to buy pieces from the ground up, and have it built. There are companies that build the frame, all of the body panes, etc. You could have a 1953 5 window pickup where it was virtually new (of course it will cost a pretty penny to do that.)
My recommendation, shop around and buy a completed project.
Here is one for example. They are asking 11,000 or so. While this would not have everything exactly as you want it, it would certainly give you something that worked to start with. Something to consider.
http://www.trucks2cars.com/car-deta...s-SHORTBED-PICKUP-1953_271134801891.html
