by 1500 watt amps, he probably means PEAK power.

A 12" Boston Pro sub can easily handle that power... 750 watts RMS.

A 10 or 15 farad cap huh?? lol... WASTE!! you dont need anything that huge.
Figure about 1 farad per 1000 watts of RMS power... so for 1500 watts RMS from the 2 amps, you only need a 1.5 farad cap. A good 1.5 farad cap can be had for about $200.

With 2 12's, I hope you're gonna have some pretty serious cusom work to go with it... otherwise you wont win crap, unless those 12's are insanely powerful and you can squeeze 150 db out of them.