I think with 4 zoner turrets, and 1 missile one the back I should still be doing pretty good against fighters (you can press the fire fowrad key while attacking something in front of you and the back missile will still launch and then curve forward and attack).
I was just thinking of putting 1 big gun in the front only turret as a just in case I need to take out something better. or when i decided to go and pirate npc ships.