Mine was a "CD turret" with extremely short range. High refire low energy cost. Would act as a "grapple", tethering the ship somewhat to you (not letting it cruise away). Other suggestions along same line is make a paralyzer turret that does mostly shield damage but still has the effect o powerplant. Make it short range too. You could drain an enemy's power if you could get in close and then finish him. Good combo with the CD turret--give them like 150m range and would make fighters a threat.