Looks good, but you may want to upgrade to an aftermarket head unit. Especially if you'll be running an amp and subs. That way you can get at least front and rear RCA low level pre-outs so you can still fade front and rear. You'll lose that ability if you don't have an aftermarket head unit (with a line level converter). Plus, you won't be getting the most out of the speakers you've chosen. It is a much cleaner signal if the amplifier gets a low level (RCA) input as opposed to a high level (speaker lead) input. You tend to introduce a lot of noise into the system when using the stock head unit. And the sound quality is night and day between stock and aftermarket head units. Pioneer and Alpine make stock GM sized (1.5 DIN) radios, if that is your concern (others may also).
Personally, I would go with a Kenwood KDC-X459 single DIN unit. Lots of features and plenty easy to use. Plus, you can get them on Ebay for like 169 bucks! [img]smile.gif[/img] AND it has 3 sets of pre outs, including a non-fade for the subs (so when you fade front to rear, it doesn't effect the power going to the subs)!
I'd also go with two amps. That Alpine would be fine for your interior speakers, but you'd be really underpowering the subs... You wouldn't get much sound out of them. Especially JL's. The experiences I had with JL's have been that they like a lot of power. [img]smile.gif[/img] I'd send at least 200 Watts to them. So you should get a 4 channel amp for the interior speakers (you don't need more than 25-30W a channel for daily driver use), and a decent bridgeable, 2 channel for the subs, one that is stable down to a 2ohm load. Rockford Fosgate and MTX are great choices. But there are many more good choices too. I have never had good luck with Alpine, they tended to heat up and shut down easily when I used to be "into" the car audio scene. Maybe they are better now?
The reason you can't find the Kickers is that they don't make them anymore, according to my local stereo shops. They suggest using their VR series for infinite baffle (free-air) applications now. Bummer. I wanted to use them too.
Pioneer also makes free-air subs.
You'll end up spending a little more this way, but your best bet would be to do it once, and do it right the first time. [img]smile.gif[/img]
Just my $.02. Take it FWIW.