As for fighting styles, its all up to you. Kung Fu and Karate both require combat states as you hit higher levels.  Aikido does not require any combat states at the higher levels.  It's a matter of choice or lazyness if you don't feel like getting your opponent into a combat state.

As for gunman, I would highly recommend Pistols.  Submachine Gun moves are mostly outside of combat. Rifleman is the same. Most Pistol Moves can be used in and out of combat. 

As for myself, I use all of them, but thats the reason why I'm broke...