Halloween Costume Ideas?

O.k. I know it's a little early, but I'm trying to decide what to do for the kids Halloween costumes this year. I would like to do something for Ryan and Peyton that are related or match in some way. I spent an hour online this morning looking at costumes. I've only found a few things I like. I found an adorable Peter Pan costume for Ryan and I could have Peyton be Tinkerbell. Or, I found a cool Superman costume and Peyton could either be Supergirl or Wonderwoman. I'm so not into super heros at all....is Supergirl a real character or just a cheesy excuse to have a girl superman costume? I used to like Wonderwoman and the costume is really cute, but will work if it's not cold since it is sleeveless and has a skirt. Wonderwoman doesn't have a male counterpart does she? Anyhow...let me know your thoughts!