I had some trouble finding rear shocks, parking brake cables, and 16 inch wheels and suitable tires. You find a long stepside bed you let me know. I can't think of much else that can't be found while looking in the C10, C20 areas.
Inline tube made some cables for me based on an old one I had. Shocks on ebay were hard to find, but once I found a good part number a few came through. Wish I bought some areas.
Condition? My 66 is wretched and beastly in the same breadth. And I don't want to change it.