These are the resources I have found for Commedia Dell ‘Arte masks, and performing troupes.
i Sebastiani – “the greatest Commedia dell’Arte troupe in the entire world” headquartered in Boston, MA USA web site; has resource links
Austin Commedia Society – theatre troupe in Austin, Texas dedicated to exploring commedia dell ‘arte theatre
Commedia Dell Carte – literally “the cart theater”; traveling troupe originating in Texas
Zap a Lot -Improvisational theater in Hamburg, Germany
Source – explanation
Commedia Half Masks – Original Theater Masks by John Becker
Commedia Dell ‘Arte Class Plans – a series of class plans written by the Mime Guy
Masks.Com.Au – Leather Masks and Original Art by Jennifer Stannard
Workshops: past and present
Accademia Dell’Arte – year round school in Arezzo, Italy featuring training in dance, voice and theater. Features work in commedia dell’arte year round.
Theatre Commedia Dell’Arte – Roving Classical Commedia University; workshop training
Workshops by Kompani Komedi – not in USA
XXI International Training Session in Commedia Dell’Arte – Directed by Antonio Fava Reggio Emilia, Italy 1 – 25th August 2005
Commedia Dell’Arte -International Workshop – workshop held in Venice in 2004