This is just my opinion but I'd rather have some good rifle, handgun, and shotgun training under my belt and have a good solid grasp of firearm fundamentals as well as the strengths and weaknesses of the major types, whether it's a rimfire rifle, .38 revolver, .45 ACP 1911, .308 bolt gun, or .223 AR-15.
I've always heard that guns availability usually isn't a problem in tough areas. Knowing how to use what's available (or what you just picked off the body of a bad guy you just klonged on the head with a softball bat) is the key. In other words, it's what's between your ears that saves your @$$.
Another way of putting it: If I had to choose between
-A guy who's had 30 hours of professional training with his SKS
-A guy who has $10,000 of any combination of fancy guns you can name but nothing more than a few weekends of plinking.
I'd pick the well-trained SKS dude to watch my back every time, because he knows what he can and cannot do.
Having said that, I'd like a .223 AR-15, a scoped .308 bolt gun, a .22 LR rifle, and a .45 ACP handgun. Might as well toss in a 12 gauge.
Edmund