High school musical "Grease" audition, in need of song and monologue ideas. Help?

I am auditioning for my High School's musical of "Grease". I'd like to go out for Frenchie, second choice Marty, or any Pink Lady. I am in need of a good song to sing 16-20 bars a capella, and a 30-60 second monologue to sort of fit that character! Any ideas would be much appreciated!