hilarious! i've only been to one (in vegas, where else? ) and the food was yummy but not really related to the theme. here are some suggestions off the top of my head:
My roommate had one of these a year ago. We didn't really have a theme to our food, just what we thought would be good. We served cookies, chips and homemade salsa, and fruit salad. The salsa was a hit (naturally, since I made it)