"...draws a lot of people..." is the key. I would bring a machine that doesn't sell for a lot of money as most folks won't put up thousands for an impulse buy. Maybe in the $400 to $700 range if you really want to sell it. But if you're just looking to get exposure for Pintastic, bring a game with a well-known theme, easier or folks to relate.
Good luck, let us know what happens if you take one.