I would suggest looking at the bounty offering and picking a branch that offers the weaponry you want, if you feel you need stronger weaponry.
Just off the bat, Catgirls do great with suppressed pistols. A pistol that does 40 or so damage per shot is a good choice.
Other good weaponry that can, potentially be in your range is the Big Ben SMG, a monster even for barely trained peasants. Fo not even need trophies for it.
These are options that do not take great investment in advancement.
Another weapon line that might take some luck or research to get are golden weapons. A rifle, smg or pistol go well with your catgirls, but making the ammo for them is kinda a bitch, but if you do, you have a reliable midgame firearm that has enough punch and accuracy and can even go to space.
But if you are researching, try and head towards armored cars. A 14mm AC is a BEAST, and well worth the investment to get, despite possibly delaying Back to School via gnome.