I have always found it hard to give away fish once they have been in my system for a while, I just get too attached to them. It would be a toss up for me between tangs and butterflies, all of my tanks have had at least a tang or butterfly or usually both. My existing setup is the first I have done in a while that doesn't have a BF. I personally love the look of the copperbands and have always wanted a saddleback BF. My favorite BF that I have kept was a trio of heni's back in the day, very active and hardy fish.