I'd like to take a second to straighten out a few misconceptions...
1st. The sub box needs to match the specs of the sub going in it... NOT just wear you want to put it. Sure it will work, but you'll lose some of the sub "ability" if you use an incorrect size box.
2nd. While a ported sub "may" have some more "boom" it is because it is easier for a ported box to go down to 20Hz. it also takes "less" power to run the sub. A sealed enclosure will require more amps power for the same output of a ported box. But, the bass will sound tighter. I disagree that rap doesn't need tight bass... In fact I would say the opposite is true. With all the "bass" going on, you'd want the bass to be tight, or you'll end up with "muddy" bass. Don't get me wrong, I'm not saying a sealed box is better than a ported.... just really two separate kinds of bass output.
3rd. Since you already have a factory sub, you could use the same location. Most likely will require a custom fiberglass enclosure, but the benefit is an enclosure that can be made the correct size, also you don't loose any storage space. Here's a pic of a 10" I have in the my stock location. It's a 10" JL audio sub. (even a 12" will fit)
For amps, you can pretty much whatever you can afford, I suggest one of the Alpine PDX amps, get off eBay for a great price. can be had in 1, 2, and 4 channel, and the mono comes in a 1000W, which would work running both of you subs.... I think there's 500 or 600W version that would work as well. Don't worry about the power ratings, as long as you adjust the gains on the amp you leave yourself with lots of headroom, and a plenty loud sub system.
That's all I can think of at the moment. If there's any questions, feel free to ask...
Good luck!
Breezyjr
