If your amp is 1 ohm stable, then it'll handle 1 ohms as well as anything else in between. Just don't go below 1 ohms. As for your 1200w, is that rms or peak? A cap will help somewhat, but as soon as it's drained, then it'll put more strain on your power system. If you're trying to avoid HO alternator, then it's a bad choice. Go to Accessories section and read up on HO alternator vs Cap.
another Q(im horrible about amps) when you wire all your stuff up, do you set your amp to a 1ohm load or 2ohm load or does it recognize the load coming from the way the subs are wired in? that was probably one of the stupidest questions ever but o well
The HO alternator is not just for competition. It's for everyday use in your car. Without it, you can destory the stock alternator/battery anything else that's sensitive in the car. If the car has to be off, then as long as there's ample supply of power, a cap will help somewhat. A capacitor will store and release power at a faster rate than alternator/battery.