If you are looking for an all seafood restaurant, I would go with Alle Testiere or Boccadoro. The ambience at both is different from Antiche Carampane. Alle Testiere might also be closed part of August.
Osteria alle Testiere, Great fish. Two seatings, 730pm and 930pm, because the room only holds about 24 people. Make your reservation early! -- which you can do via email. http://www.osterialletestiere.it/Test... firstname.lastname@example.org