Get the factory system. That Fosgate system is pretty good, but not as good as a good aftermarket setup. This is what I would do.
You buy a new car, with a warranty, and why loose part of the warranty by adding something aftermarket? The SE-R Spec V is awesome from the factory. Just get their factory fosgate system with that 10" sub. It'll do fine if you're not crazy for music being loud like a concert. IF you do want it loud like a concert, invest in a Clifford $500 alarm system, $200 of dynomat, the stereo and some ear plugs. Your car will eventually start raddling from the mirrors to the interior.
If you build a system, I would recommend Dayton Titanics better than anything else on the market for the price. Go to:
http://www.partsexpress.com/pe/showd...D=117656&DID=7
It sells for $140 but when it's put in an awesome box, it'll blow you away! I've got their older version in thier titanic 1" mdf dado sealed box and you can feel the bass throughout the car and you can feel it outside the car too. Before I had two of them in a vented box and man, you could feel the air moving when you breathed through your nose. You could even feel the bass through your body and your hair. I hit well over 135db in side the car.
I'd also recommend using Ultimate full-range / component sets. They are reasonably priced too. You can get both the Ultimate speakers and the titanic from
http://www.partsexpress.com If you want an alternative to the Titanic MK2, get the Ultimate ACW 1000.
http://www.partsexpress.com/pe/showd...ID=16057&DID=7
That way you could run all the same brand components. I wouldn't spend more than $140-150 for each $10 sub. These subs have awesome specs and I've had a 10" titanic and I know what they can do. You'll be very happy if you like loud/deep/accurate bass! 2 of the titanic's vented (25hz tuned) and even in a dual sealed .75 cu ft box will out bass 3 powerful JL 10's sealed (not the w7's, those are pretty awesome but cost a lot of $$$$$$$$$). I'd go for the Titanic for tight accurate, deep bass below 150hz, I'd go for the Ultimate for bass below 320hz (more rock & metal music that has lots of mid bass kick) w/ a little less deep bass quality. I think the Titanic has 5x the warranty than the ultimate.... I'm not sure but mine has a 5yr warranty.
Here's the specs:
$140 Titanic MKII (300w rms / 425w max)
Power handling: 300 watts RMS/425 watts max. *Voice coil diameter: 2" *Voice coil inductance: 2.48 mH *Nominal impedance: 4 ohms *DC resistance: 2.5 ohms *Frequency response: 25-400 Hz *Magnet weight: 84 oz. *Fs: 28 Hz *SPL: 90.2 dB 2.83V/1m *Vas: 1.35 cu. ft. *Qms: 9.55 *Qes: .43 *Qts: .41 *Xmax: 16 mm *Net weight: 19.5 lbs. *Dimensions: A: 10-15/16", B: 9-1/8", C: 5-3/4", D: 6-1/2".
$150 Ultimate ACW 1000 (300w rms / 600w max)
* Power handling: 300 watts RMS/600 watts max * Voice coil diameter: 2-1/2" * Impedance: 4 ohms per coil * Frequency range: 25-400 Hz * Magnet weight: 120 oz. * Fs: 24.6 Hz * SPL: 89.4 dB 2.83V/1m * Vas: 1.22 cu. ft. * Qms: 9.43 * Qes: .42 * Qts: .40 * Xmax: 16 mm * Net weight: 12-1/2 lbs. * Dimensions: A: 10-5/8", B: 9-3/8", C: 7-1/4".