I would say you are unlikely to find 5 inch Crosshatch as you can't differentiate Male and Female at that size I don't believe. They are not going to eat Tangs, but in my personal experience having a pair right now, 120 gallon is FAR too small a tank for Crosshatch. My Male makes my 240 look small. He paces the tank more than my same sized Sohal Tang, which is saying a lot.