Thanks guys.
My Kole is very small, no more than 2 inches nose to tail, so I'm hoping that there will be minimal aggression, but that's a good tip about using an acclimation box, I'll see if I can find one.
Out of the fish mentioned, I'd love a powder blue, but I've always thought they might be a bit too big for my tank. I have no plans to upgrade so whatever Tang I get needs to be happy in my current tank even when it reaches adult size.