IM HERE!!!!! lol. You could get away with 300 for a banded. For coral cats, I would go for a tank 180. Bandeds get 3'+, and need to be able to orient themselves along the side of the tank. That means you would need a tank 8x3. Corals cats are more slender, so a 180 is ok for them. They get to a maximum size of 27", but a 180 could work. I would look into selling you banded and replacing it with a coral or marbled cat. I am talking about the atelomycterus mormoratus (coral cat) and atelomycterus macleayi. You shark (chiloscyllium punctatum) should have a tank of 300+ gallons. Good luck with your fish though! And remember, bigger is always better! Try to avoid puffers and triggers. The best tankmates are groupers and tangs.