Really, you guys. They were in a display tank of about 240 gallons. It was mostly plants, but there were four or five of these monster discus. If not 12" I guarantee they were at least 11". I'm looking at my Oscar right now. Yup. That's about the size. Heck, I'll call them on the phone and ask right now.
EDIT: I called, but the girl said they never measured them so she didn't have an exact measurement, just that they're still the biggest she's ever seen.
At least check out these 9" 'ers.
http://www.monsterfishkeepers.com/forums/showthread.php?t=219344&page=2