I (and I think you were there too, Charlie, if memory serves) went to a "rave" at the haunted house next to Walt's. That'd be an interesting place. Haven't the foggiest who runs it. Other obvious ideas might be Sideshow, Eastside, cafe berlin. Hell, maybe we can rent out gumby's for a night. Or one of the ragtag theaters.
Charging money - at least a donation jar - is imperative because doing it to be altruistic is for organizations that can afford it. COMOPOLO is monetarily worth what our collective monetary worth is (read: not much). People don't mind throwing in for a good cause. And we're so damn cute and adorbs.