There are a ton of places on 192....everything from Denny's to IHOP and the like. You'll find a slew of restaurants in that area who'd be happy to seat you. I find the pancake houses and Denny's aren't crowded at dinnertime. The Golden Corral near Downtown Disney is our favorite place, the Buffet is huge and they'd definitely be able to sit 20 and you'd all eat for a song.
My one and only suggestion would be not to arrive at 7:00 pm looking to be seated....either go at 5:30 or maybe call ahead for a "reservation".
Funny side note here, we had PS's for Ohana and someone actually was behind me (at 6:30 mind you) trying to get a table for 12. They waited over 2 hours....talk about a waste of time.