long horn cow fish & Cubicus Boxfish in a reef?

[Octupus]

i am so tempted to buy one of those into my 180gallon (soft coral) reef tank. I have a couple of clowns, a purple tang, a mandarin goby a watchman goby and an empror angel (adult). Any suggestions? I know few have mentioned that it is not good idea to put these fish in a reef. Thank you and Happy Holidays!