gmcyukondriver
Built, not bought.
I'm thinking of trying the lift gate barn door combo. Theory says it's possible. Just need to get my hands on a lift gate style rear end, without buying it new... Never actually seen one up close.
If you'd like pics of mine, I can get you some. The only problem I see is that the liftgate latches in the middle of the tailgate, so I don't know how that would work with barn doors. It would definitely take some design work, but should be possible.