I was thinking that since this is our first time there, we should approach this similar to the Girl Scout event. No coordinated display; just bring whatever you want. It would be neat to have various themes represented, for example: Town (me, Greg, Ben); Space (Evan, Dan, Dan), Modified sets (Nick with the Star Wars carousel; Modulars/modular compatible (Joe, Josh with the Whipped Café); Microscale (Micah, Aaron); Trains (Laura); etc. It does not have to be a huge amount of stuff, just a variety and good quality.
Easy and interesting display. Sounds like a good plan.