Which of these three do you most prefer,and which do you think would be best for my tank? I all ready have 10 black skirts but I may change them out for one of the other two listed. Current tank mates are four baby firemouth cichlids(trying to get a mated pair) and a male bristle nose pleco, I may add hoplo catfish later on. The tank is 55 gallons.(I only want one school)