If I were able to bring the cichlid and unload him to some place. What could I put with the pleco and shrimp in the 20g Long? I like tiger barbs. I really don't like tetras that much.Don't get a puffer. They are viscous unless kept with an even more aggressive fish and even that isn't a sure thing. I have one that killed 2 plecos.
I'm not a fan of Africans, I see them as a dime a dozen. He's a good looking fish, don't get me wrong. Very beautiful, but I would pick the pleco over the cichlid in this case.
You could add some tetras or some other schooling fish to add movement to the tank.
In a larger tank you could get away with keeping both fish, but you'll be pushing your luck putting them together.