No there is no algae eating shrimp that won't be eaten by you peacock bass. A better idea would be a temporary pleco until your algae is gone and then return it.
MoSt pleco don't eat algea. Get a uv sterilizer, use diff lights, or less light. Why so much algea to start? I'd look into the cause more because it is a battle you will prob lose unless you can find the source