My favorite local "channeler" of Janis here in New Orleans is Irene Sage. She does a good job covering Etta James, too.

The sound clips on her website are all originals, and I'm not sure which (if any) best showcase her Janis-like qualities.

I don't know if she'd pass an audition to play "Pearl" in a play or movie, though ~ too blond and too glamorous!