I've always had a thing for Jack Dempsey's and purchased two just recently, which are living quite happily with two convicts. The Dempsey's are almost two inches, convicts are 1.5" and about 1 but definitely hold their own. They're also staying away from my pleco which is nice. I am planning on upgrading to a 300l tank, maybe bigger, I have no idea, all I know is they're going to need more room soon enough, and bigger is always better when it comes to fish tanks!
Now i'm pretty sure i've limited my options by having a real thing for fish that can't be kept with much else, but does anyone keep these species with other things? I like watching the 5 of them just doing what they do but I keep thinking there must be a way, provided there is enough space and hiding spots, to keep similar species together. I guess it's all trial and error, i'd rather not risk it too much, but if anyone has any suggestions i would appreciate it!