Just a thought. People's attention span is pretty short so brewing beer at the event will probably lose most folks. How about a kiosk with a short video that goes through the steps, but skips the "waiting" time. Have it continually repeat. Then have a display of the various ingredients & tools. ie. barley, hops, yeast, mash tun, BK, burner, IC, kegs, bottles (demo bottle capping) etc... Maybe a flow chart of the process on display as well. The guys running the booth can be there to answer questions & get into more detail for those you "hook". Cheers!!!
Another brain fart: Set up a one keg system to demonstrate how easy it is to configure & use, with water of course...