If you carry a gun you multiply chances of being shot (when you taking it out)

@Moonshake disagree with you on judo, i am judoka myself, but i would rather add judo to traditional MA. It is effective, but even the way you spar at judo is kinda nonstreet.

Me personally would recommend Sambo (i switched judo to sambo at one point), which is basically KGB version of judo, with punches and kicks. Also Sambo itself concentrated around effectiveness, not stylish throws, kicks or punches.

And of course the best defence from big guys are fast legs