heh, my capships are all turrets with the exception of one larger weapon such as a mortar. However my Osiris has a heavy mortar as well as 2 inferno cannons. The rest are turrets. Mind you I hate having missiles. They take forever to fire and drain too much energy for my liking. Then again common sence states not to use a battleship against bombers as they're hard to hit so I'd just switch to a fighter and it becomes a different story.
But my usual cap ship lay outs are all turrets with larger weapons (ie. mortars, razors, infernos) , the amount depending on the ship type.