Ideas for a kid's birthday's refreshments?

I'm hosting my little sister's 6th birthday party. She's having a theme where she and her friends get to pretend to be grown-ups going out for dinner, dancing and a movie. My friends and I are in charge of the waitressing and the entertainment...and the refreshment ideas. Since they're kids pretending to be grown-ups I've already decided on Shirley Temples, Virgin Pina Coladas, milkshakes and punch. My sister's decided on the music I'm downloading for her and the three or four that I'm singing, but I need ideas on good movies, refreshments, and dances for little kids! I also need to find a place where I can find really cheap waitress outfits! HELP ME!!!!!!!!!!!!!!!