Get a copy of
Vintage Truck magazine, also
Classic Trucks, both are geared toward folks taking old and making it new. Classic Trucks in particular features ads from builders who sell complete chassis ready for bodies and mechanicals. You can build a whole new old truck from parts.
As to the VW, that's out there too:
VW Beetle Chassis (Beetle Floor Pan), OEM VW of Mexico, Swing Axle Rear, Ball Joint Front, Pedestal Seats - Aircooled.Net Volkswagen Parts That was the first place I looked, there are no doubt plenty more owing to the evergreen popularity of the air cooled VW.
Good luck in your search.