I agree you should get something from RE audio here is a RE SE12D4 12" 600W RMS Dual 4 Ohm for $99....so you can have two for $200, plus the shipping and they are by far better subsPlease dont buy these. They might get loud but the sound quality and overall sound quality ***** on them. I had one(well two) sealed and ported and it was just a big pig and my 600watt mono was able to blow it without any problems.
Pick up something from the RE Audio line. You amp would not be enough to power two 12 woofers btw. You can get two RE SE12 woofer(amazing btw) for $220-$240.
You are going to have to change amps if you plan on running two of them though.
Kevin