Tang?

[Black Phantom]

The whole idea of creating a reef system is to find the correct balance and enable your fish and corals to live a happy stress free life. Fish need room to roam, otherwise they get stressed out and will probably get sick or die.
Some people will get lucky and have an oversized fish that does well in a small tank. But do you think their happy.
Go with smaller, more colorful fish for now and if you think you absolutely have to have a tang - get a bigger tank.