Is it smaller than this?
The day after I bought my '01 the stock battery pooped the bed (luckily, in front of autozone). So I put this one in. It's running a 500W RMS amp right now with nearly
no headlight dimming, even when the subs go from not playing to full drop. You shouldn't have a problem unless you're REALLY pushing it, but two reasonably sized amps should be alright. Mine was $90, so if you're worried, take the hit. Bigger problem will probably end up being bottlenecking in the wiring or the alternator if it becomes that much of an issue.
Don't bother with a cap, unless you want to cut headlight dimming. But even then, just get HIDs and problem solved!