Andrea gave me a tip that if you like the Puppini Sisters you might also like The Blue Dolls which is a vocal group from Italy.
The Blue Dolls consists of Erika Celesti (soprano), Federica Pallante (soprano), Viviana Dragani (alto) and is backed up by Marco Parodi (guitar), Paolo Volante (piano), Riccardo Vigorè (double bass), Luca Rigazio (drums).
You can listen to some songs from their album on their website.
On the album they mix swing jazz standards such as Shoo Shoo Baby, Sing, Sing, Sing and Some Of These Days with Italian songs from the swing era. They also sing a version of Charleston and even the blue grass song, Down In The River To Pray, that you might recognize as the song that the sirens sing in the movie Oh Brother, Where Art Thou?.
If you like retro stuff, you also might want to check out one post from my archive where Christina Aguilera sings "Candy Man".
What do you think of The Blue Dolls? Please comment.