Here are some songs that I've seen done by various showchoirs that worked out well
Eye to Eye - A Goofy Movie
Birdland - Manhatten Transfer(A bit tricky vocally)
It's My Life - Bon Jovi (The males are prodominent-sp?)
Diamonds Are A Girl's Best Friend - Gentlemen Prefer Blondes/Marylin Monroe/Moulin Rouge(You can showcase the gals in this one!)
Disco Inferno, Celebration, Carwash, Saturday night Fever, Staying Alive - (Alot of disco songs work well for ensembles or any medly of...)
Trashin' The Camp - Disney's Tarzan (I saw this done once and it was really neat with bowling pins and foam bowling balls)
It Starts in the Heart - Disney's Jungle 2 Jungle
Check out this Website... it's Attache 's Show Choir website. They are phenomenal! Listen to some clips and get some ideas.
http://www.attache.org/sounds/
"You just have to do what your voice tells you to do." -Linda Eder