Very Cool,I would sugest a cat shark of some sort.As for equipment I would use a sump with live rock in it and chaeto with an over sized skimmer ,much like a SPS reef setup.As for aquascaping I would go with fine sand for the bottom about 2-3 inches thick and some big cave just a couple so it can hide from the light of the day,just make sure the rocks cannot fall on the shark or be knocked over by it.Leave plenty of swimming room for the shark.I would go with a tank around 200 gallons or larger.I would aslo use led moonlights so you can see them in action at night,Make sure your tank is well established befror adding your shark.You can bump start this by using water out of a good clean system that does not contain copper and by using well cured live rock out of a established tank.I would also reccomend buying a ro/di unit for the water this help the cycling process to.Good luck and I hope this helps,feel free to ask more questions,Chris.