Newer the better, ideally know the seller. I've had a variety of headaches with mine, that although have taught me a ton about most of the bike, have kept me away from a reliable ride til now, and even now I may not have one heh.
When I was buying I was the fool who thought local was better and the ones on the board for sale were too much of a hassle to deal with, however I would consider it if I were you. Knowing the history of the bike is going to be your biggest issue. It is all about how it has been maintained, and if abused at the drag strip or stop light to stop light. Good luck bud