In my opinion there is two main type of baits. There is the fish baits (Pilchard, Mullet, Kahawai, Bonito ect) and they work well on most Sharks, Red Cod and Kahawai.
There there is the Crustacean (Shrimp, Prawn, Crab and Crayfish) and Shellfish which work well on Rig and Moki but would rarely catch other fish (which can be a good thing if Dogfish and Red Cod are in plague proportions).
I consider Squid somewhere in the middle between the two groups. In reality its probably has more in common to the fish baits then the Crustacean.
For starters a good range which is easily available would be Pilchards, Squid and Raw Prawn.