If you don't mind spending some money, you could sign up for Splice Sounds; for 8 dollars a month you get 100 credits per month to spend on any sample you want (and you can preview the samples before buying). There's a lot of vocal packs on there, I recommend the black octopus sound ones and the bright lights vocal pack.

If you don't wanna spend money, you could do some digging to find some on Acapellas4U. Pick a pop female vocalist and you'll probably find a few vocals to chop up and play with.