Depends on what you're going for... Both will add a foundation to your car and will get things moving... A LOT! But I woulnd't get the Alpines just because your full range speakers are Alpines.
I like JL but the higher lines are pretty pricey. I'd personally get a single Type R 10" sub and run it with a an amp that can put about 200-300 watts to it. Most people that haven't been around subs a whole lot are pretty suprised how much sound a single 10" sub will put out and they don't need tons and tons of power either.
The Kickers aren't bad but I think the sound quality is much likely to be better with the JLs or Alpine Type Rs.
