First thing to do, is find out what town/city restrictions are for BBQ. I read on here somewhere, similar to this thread, that some towns/cities Health Dept will only allow electric smokers or the like. Now thats not concrete information, but its something along those lines. Id hate for you to have an idea in your head on your plan of attack, and then realize at the last minute that you'll have to completely change the way you do things because of something that you thought was obviously Okay.
One idea that I always thought would be good was to have some sort of a mobile setup, and sell PP sandwiches at farmers markets that are held in grocery store parking lots. Kinda of like the way they do brat frys.