You have such tiny magazines, you should default to box launchers. If you took off the magazine and added 2 additional boxes, you'd get the same firepower for less size and higher salvo size. You should be able to get a 250-500 ton fighter out if you strip it down - and remember, it does need to be stripped. These aren't warships, these aren't even ships. These are "boats" that are too tiny to survive in open space on their own. It's a rowboat in the ocean. Mount 1-2 box launchers and give it a 20 hour fuel life (or 1 tiny fuel) and nothing else. They can't do much, they won't do much at all, that's not the point. The point is that if your missile ships are packing 10 launchers each, then you could build 5 fighters in a month to fill 1,250-2,500 tons of hangar space. My usual design for 5 or 10 hangars for a carrier might load 10-20 fighters. What they lack in power they make up for in numbers and cost. They can deliver a payload at greater distance and let your missiles have more warhead and less fuel. This is the task of the missile fighter and this is the only task. Your fighters are not concerned with point defense, armor, shields, jump drives, fuel, or maintenance. I often leave mine without any maintenance spaces, actually. The 0 maintenance life doesn't matter when they're only out fighting for 3 hour skirmishes and then back in the carrier.
Also, what engine tech is that? Many people rightly argue that you shouldn't bother with fighters until you get magneto-plasma.