@Magnum Man If you are looking at SA Cichlids, remember the rule of the skilled aquarist. The fish that would never have gotten large when you were starting out, because you would have killed it, will thrive with water changes, space and good nutrition. Now you have to assume they will reach the maximum size for the species, which for something like a red shoulder severum is pretty big.
A big severum could terrorize shoalers into shoaling....
Lemon tetras are one I've kept, but just don't get. With all the beautiful tetras out there, they strike me as dull. They are peaceful, though males dislike each other.
Pristellas, meanwhile, are beautiful little guys, though the 'fancy' mutants sold here are ugly compared to the cheerful little wild forms. They're way smaller than lemons. They behave more like a herd of deer than a shoal - they spread out and feed while watching each other. I guess the principle is if your buddy across the way starts running for it, or gets eaten, that's info you can use in life.
Pristellas will be wonderful snack food for an adult severum.
I have kept and bred angels. If you get a group and one becomes the target of aggression, you will rapidly have angels in 2 tanks. They never seem to stay in one tank, because they can be straight up nasty in groups. A nice smooth group is a stunning sight, but you have to know they killed some friends to get to the smooth stage. If you have two tanks and are getting SA Cichlids, keep one as open space and a refuge.