Here is the javelin class frigate in a semi-PD configuration with modern weapons (I have not made the really old tech weapons yet):
Here is the gnat class interceptor with a venture outfitted with reloading atropos & EMP torp launchers:
Currently the javelin is a fairly versatile hull sporting 4 ballistic turrets and a pair of missile hardpoints, all small size. It has nice speed and hull HP, but low armor and no shields. I might decide to have the 'very old' ships have decent armor as well, but still lack shields - differentiating them from the higher tech low tech ships which at least have shields, and remove some of the extra hull HP, since right now its not uncommon to have charred looking javelins flying about with almost perfectly intact hulls because the paper-thin armor got fried off by some interceptors.
The gnat comes in packs of 6, costs a single fleet point, and repairs very quickly. It also a whopping armor rating of 5 and 50 hull hitpoints. So a single flak shot should be more than enough to take them out. Their very low survivability is offset by having a tiny size and a miniscule hitbox, not to mention incredibly high speed and a pair of light machine guns. They fail abysmally when used without a carrier for support, but given their superb running away skills, can be a severe pain for ships lacking beam or flak point defenses, as they can escape and come back at full strength.
The venture in the second picture has some underwhelming guns, to offset the high OP cost of the torpedo tubes.