Just to throw another one in there, you could try elliots cichlids (Thorichthys ellioti) colourfull, active, get to about the same size as convicts and not nearly as agressive
And do you know the availability of these in Canada, perhaps? I can't find a lot of the species that I see posted on here in Canada. (Where I live in Canada, at least) At one point, it was hard to find kribs!