True Green Terrors are real terrors but they pretty much disappeared from the hobby over a decade ago, you can get them from reputable dealers though. The commonly known Green Terror is really the Gold Saum which isn't all that aggressive but is no slouch either. Most of the GTs out there are Gold Saums, some Silver Saums.
since im still in school and summer is coming and im going to have alot of free time im gonna take my empty 20 and make a little sump out of it. I'm hoping this will help keep water quality better than just a HOB or canister.
With territorial cichlids, the tank's footprint is a major factor. In terms of bioload, IMO you'd be fine, but it's not always just about the amount of water diluting the bioload.
Just ask your dad if you can have the wall space to the ceiling where the current 55 is and stack a few more in that spot. Make a custom stand..........should be able to fit 3 to 4 in there.