Whats better a power acoustik or tsunami capacitors?

I was trying to get a capacitor for my truck, and I have a JL 500/1 amplifier pushing two 12's and I wanted to get a Capacitor since an extra battery wouldnt fit in the back of my truck, so I was hoping to see which brand is better and what farad should I get 1 or 2 or maybe more? thanx (any other good brands out there for capacitors)??