What should i use? a tsunami 20,40 farad capacitor or a kinetik battery?

right now i have a optima yellow top under the hood(870 ca and 750 cca) factory altnator(140 amp)polk audio mid/highs,audiocontrol 4xs and a audiocontrol overdrive and 2 rockforfosgate amps.both combin for 110 amps(60+50 amps) both requires 8 gagues power/ground.i will be useing 14feet of 4 ga monster cable power wire .both amp combin for rms power is around 800-900 watts.will a big capacitor help me better or a battery?will a second battery put a strain on my altnator?