Depends on if your green terror is mean or not IMO. Green terror might decide it doesn't want to live with all those little friendly fish. Replacing green terror with a blue acara would make it a more sure bet.
I see you said the 50 gallon would be for wet pet of your dreams, any ideas so far? 50 would be too small for many of the common "wet pets" like midas/red devil, parachormis, etc. Could house a male cabuya convict, that would probably be biggest fish I'd keep in a 50 for life.
And I have used the SunSun canister filter. I had it for a couple years and had zero problems with it, I liked mine. However I know a couple members have posted that theirs sprang leaks.