I will put up a list of them if I can but as far as 3d modeling goes, they area just about all different. Narwhal and Nautilus were huge (might be able to get away with throwing Argonaut in with them) the dolphin was a shorter one off (319 feet compared to Narwhal's 371), and then you have the Cachalote and Cuttlefish which were even smaller at 27. The C class really has that fleet boat shape though but, just a good bit smaller. They had MAN Diesels too but were reengined before the war IIRC
USS Dolphin SS-169 (V-7)
http://www.navsource.org/archives/08/0816909.jpg
USS Cuttlefish SS-171 (V-9)
http://www.navsource.org/archives/08/0817108.jpg