That pic of the female convict isn't even her in breeding colors. That blue/gold iridescence is just the sign of a healthy convict, and is on nice quality males as well usually. =) They're TOUGH as nails to kill, trust me. I'm always impressed with how hardy they are.
That being said, a nice big male or female can be gorgeous... but also is probably one of the most aggressive small/medium cichlids you could pick up. I'd argue that a BP is a much better choice if you want tankmates that aren't shredded. Eaten isn't the problem with convicts - torn to bits and pieces is. No matter how big the fish, they can always be shredded if convicts really don't want to deal with them.
Cutteri, nanoluteus, Honduran red points are friendlier. I also really love my severum, and I think you could keep a single adult in a 46. They're DEEP fish though, so sometimes it's a bit more cumbersome looking. Related to the BP in theory though.
I used to have a knifefish - one of my favorite fellows. Could be handfed, had all sorts of weird habits, would lie in my hand. Bichirs too. However, for both, you'd choose a smaller species - a polypterus senegalus for the bichir would work, and maybe a brown ghost knife. Both I found to be great in a community tank, provided the fish in said community were too big to fit in mouths. I never found them harassing anyone, just eating them if they were too small, haha.
I would recommend against a JD - I've seen full size ones kept in 55g and thought it looked too small. They're also going to be tricky to keep with anything else: see what I said about convicts. The bigger, thicker fish you can keep with them, but then you'll have a very crowded tank, haha. And a 55g is a 4' footprint, whereas 46 is a 3' one, right?
