I can imagine with colors like that, they would be expensive. But they are really impressive. To hell with a biotope if you can throw something that beautiful in there! Hope Taz's answer is what you're looking for! I've got my fingers crossed.
Yea, I've seen Heiko Bleher (most famous biotope guy in the world) put sword tails in his African tanks.
I've found these and just love them:
Nerrr... I wanna try it. BUT the buffalo heads are cichlids. Problem? Can't get rid of the buffalos. And the ctenopoma is an anabantid. But I'm kind of okay about getting rid of the ctenopoma since it may be my biggest problem. But maybe I should bother.
I think angels and congos would both fit, maybe.....