i have a brown-banded catshark (chiloscyllium punctatum) in a 460 reef tank. they are very docile & mainly nocturnal. make sure you have caves in the live rock for the shark to hide in since they are bottom dwellers.
they grow to a max of 110 cm at which point they will most likely be too big for your tank with the rock in it.
ours eats frozen krill & knows when his stick is lowered, yesterday he was chasing our snowflake eel around because we were spot feeding him with the same stick - they have the same diet. their (the sharks) main diet in the wild are inverts & small fish. we used to have a coral banded shrimp, until "czark" ate him.
you'll be able to clean your tank without any problems.
before you get one, maybe you should do a google on them & find out as much as you can. ours hatched from an egg 3 months ago & we have a professional who comes in 2x a week to take care of our tank