I was actually entertaining the idea of getting a Dual Rockford Fosgate Punch Sub Setup
I'd love to see a pic of your set up, also is it a hatchback/sedan? Do you have the punch P1/2/3?
I'm currently running a Rockford Fosgate R500X1D amp paired with a 4 ohm 12" Powerbass w/Loaded ported enclosure
Pushing it at the 300W RMS the amp is rated for at 4 Ohms, but the birthsheet came in at 662W @ 2ohms... so it can have a lot more potential
Here's a pic of mine