[quote=Chenzor]
Why not TWO submachinegun-caliber guns on a torret then? Or a small sphere companion armed with an smg-like gun, like a personal companion? (Thinking mass effect drones)
[/quote]
The first would still suffer from being too clunky to carry around on foot while losing out a great deal of firepower, while the sphere companion would have supply issues. 

The personal companion did give me a few ideas though. I'll edit them in, and you can check them out Protagonist?