I have a common pleco in with mine, but he's an unusual fish, they're usually very aggressive with other catfish but mine doesn't bother anyone. The one I had before did though and he needed to be moved to a diff. tank.
I was about to make the exact same thread I was gonna ask could i put an Royal Panaque in with a TSNxLei. The TSNxLei is 8'' and the Panaque is about four but if the Panaque is Max size at about 12" i doubt he will do. Any other Super Duper Nice Pleco's out there? The Scarlet Acanthius is on My List 'Sorry for any mispellings with the Scarlet plec'