So much more info needed. :spin2:
Will it be a reef or fowlr? What other fish are you planning? Sandbed? How deep? Do you want a peaceful or more aggressive tank? Do you want the wrasse to perform any housekeeping chores (pest control, etc.)? Answers to those questions should get the ball rolling.
For my part, I like more peaceful fish. I love leopard and Halichoeres wrasses. Flashers are also awesome. And I love my little possum, too.
Good luck.:wavehand: