Astronotus ocellatus (spelling?)
forget live feed, unless you raise them urself.
fresh meat like beef heart and pellets are better and have better variety of protein etc. I handfeed mine.
they will pair up, male and male won't they will fight.
you can have anything with a somewhat aggresive temper and that is the same size, anything that can fit in they're mouth will soon be lunch.
don't bother with plants unless you want to keep planting them, they will uproot them, driftwood and rocks they love..as most fish do.
they are very hardy and intelligent..and I believe need to be kept occupied..
Only get them if you have the tim to spend with them. as they will soon look up to you as the "boss"
you want to filter your tank more then recommended as they are messy eaters and make alot of waste. i'd recommend more then 6x per hour, but i'm an overkill kind of guy.
gravel vac once a week, deeply once a month or more, and do large
pwc's weekly. i'd say 50% or more..(I do around 60)
honestly, unless your prepared for the time and effort they really take, I wouldn't get them.
HTH and good luck.
EDIT: couldn't help myself from jumping in quickly, they are by far my favourate fish.