I know it's a hard choice...lol Thats why the tusk is so attractive to me, I think it would be a nice fish to work around.
BUT then theres the tang, always a good choice. Either another Kole or maybe a bristletooth like a tomini. Mine is really cool when he's out, but still quite shy. lol
Or you could wait it out and when your tank is more mature get an anthias. I believe one would be good. There's some really colorful ones. I'm not 100% though, I just got one yesterday and I am worried sick. :-( So the jury's still out on the anthias, but you might have better luck than me.