Into the Woods calls for a big cast and needs some really good male voices. It is done more often than it should be, as the piece is pure Sondheim, and, as such, calls for real musicians; at any given time there can be 4 different key/time signatures going on at the same time, so you have to be able to mind your own business an stick to your part! The suggestion about FAME was a good one. My D did it 2 summers ago- the cast was huge and the kids had a ball. The dance numbers can be as simple or as complicated as the kids can handle and the vocal ranges called for span a pretty wide range. The show played in London for years- check it out and read about it's success there.
"I'm mad, you're mad. we're all mad"...
The Cheshire Cat