I would add the kole first and wait awhile befor adding the achillies. The achillies is a territorial defender in the wild so if the kole is esablished first it may work. I have a kole in a 180g. w/ 4 other sps. of tangs but no Acanthuruses like the powders, ect. I just dont trust them as far as temperment and like ophiura said, durability. But you really never know and if its something YOU want to try and willing to except the worst if it happens then, go for it. They are both very nice fish. Plus the size of your tank is a plus for makeing it work.