Getting performance rights for a fundraiser?

Hey, guys! I'm a representative of an unofficial (meaning we aren't recognized by the school, but we have staff advisers and what not) student-run group at my school. We are looking for raise money for charities that donate money towards what our group represents and the idea of putting on a show came up, because many of our members are active in the music department. We thought we could maybe put on a whole musical and if we go that way, the best way would be for us to do something classic and family oriented to get in the crowd. The most popular idea at the moment is to stage The Wizard of Oz. The school just finished it's production of Fiddler on the Roof a few weeks ago so this production will most likely not be school funded and run on donations and whatever we have available. Do you think there's anyway I can acquire the rights to The Wizard of Oz under these conditions? We do have adults on our side, though it will be a student run production. Does anyone have any ideas of alternatives for this idea? Thanks!!!