I love my Sohol and PBT. They are both pretty aggressive and the Sohol gets big quick. Powder Browns are nice also. Nasos are probably too big. I'm not sure how big the Vampire Tang Ray just posted gets, but it's a beautiful fish! I'd throw it in my tank if I had the room for another.
I have a Hawaiian Yellow Tang and A blue Hippo tang. Both are very docile and swim with the other fish from time to time. Both are not very exotic. The powder blue tang has great coloring. They had one at Petco in Newton foralmost $85.OO. It was very nice, but expensive.
Even a 110 is too small for a sohal.
Go with a yellow, a purple, a chevron, atlantic blue...
How about a whitecheek? Haven't seen many of those around.
Maybe try an Achilles? They're tough to keep, though.