Well, you could start out at your local library and search their audio visual department for sound efx cd's, educational material, etc. You can go to a record store and actually go through records for interesting sounds. Or, you could actually make your own sounds.
The answer to your question is in your question. You find a vocal you like, you sample it, then you play it.
Anything thats worth playing isn't out there just to be given away. You have to dig and find it. When you find that diamond in the rough, you'll know it.