A Clown Knife would need your whole 180 all to itself, I'm afraid to say

They also do not make good tankmates for boisterous cichlids like Oscars. My Oscar pair harrassed my Clown constantly, to the point where he wouldn't even come out of his hidey hole at night
I agree with Zombieslayer, you are maxed out on fish as it is. Best to leave things as they are
