I must say since being introduced to the larger cichlids I LOVE Green terrors, Right now I have a gold saum, or atleast I think I do, and I love the little fella very active eats a bunch, haven't seen aggression yet though I put some fish in his tank for temporary holding, they're awesome fish and look awesome, however from what i've been told and read 55g standard footprint is too narrow for them if you can try to get a tank with a bit wider of a footprint, my personal favorites are 36x18x18 or 36lx28dx24h[favorite] and of course 48x24x24, though the last might be too big for what you're looking to do.