Depends how hard you run your system. If you're cranking it to clip all the time and have no capacitor then your draw is going to be higher and your alternator will die.

If you play it like a sane person, your stock alternator will be fine (to a limit of course, a few Kicker KX1200.1's will make short work of your alternator regardless of how loud you turn it up). I have an RF 800a2 (60A fuse) and a 200a4 (40A fuse) with a capacitor and my alternator is fine. So is my battery.

If you just want some extra amperage, just have your alternator rewound. It's cheaper than getting a whole new one, and high current alternators are harder to turn, taking away power from your engine.

-Diabolik