I like the delhezis. Mine was very active and friendly, came out of his hiding spots when ever I walked by the tanks. Give them a while to trust you and you can even hand feed. I recently sold mine, but would definitely get another one.
I think a dehlz would be ok, I do like the idea of maybe a wild caught Oscar, they'd get huge though eventually. I say dehlz would be a nice addition especially from jurassic