I've purchased Zero G's Pro Pack for Garageband/Logic and it contains quite a few female dance vocal loops. You can also acquire this library in Acidized Wav format.
If you are using Logic, the last Jam Pack that came with the Logic 9 upgrade contained some as well.
....I just noticed the "download" necessity of your request. Check out esoundz.com Sonic Reality's Store, they have a download section where you can purchase just one sound clip/loop for .99 cents...they may have something you can use.