HELP!! capacitors and amps and subs lol!!

Hiya just wonderin if anyone can help me!?

I have 2 kenwood subs 12" (kfcw300s) and am about to purchase an amp either...

1) 640w rms monoblock 4 ohms

OR

2) 1500w 4 channel 2-8 ohms (probably this one)

My subs have the spec below....

150W RMS
Freq. Response = 30-600Hz
91dB
4 ohms impedence

Can anyone tell me what kind of capacitor i should buy and what features such as frequency i should look at before buyin a capacitor

Help asap would be much appreciated

Thanks!!

urrrrrr.....frequency....cap???? who told you caps have anything to do with freq?

and who told you that you even need a cap?

kick the cap and get a better alternator.