For a girl I would choose the academic gifted school in a heartbeat.
If I had a son who was gay I would consider an arts school because it would probably be a safer environment for him. But that would be a compromise.
In theory the creative school sounds great, but my experiences with local "artsy" types have led me to conclude that a school populated by them and run by them would be weak academically and probably not all that great artistically.
I hope some real artists respond to this thread. I think those are the people you need to talk to about this.