Maybe check out a si mag d4? I don't know to much about em, but I'm sure there will be a few people chime in.
I think their mounting depth is only somewhere around 5"s.
My zune sounds good on my kdc-x990. I don't hear any noticeable difference in distortion, the only thing I really notice is the volume is at a lower level than cd's, but not by much.
While I am no audio expert by any means, I think I have read on here that you shouldn't mix brands of subs. Stick with the same through-out.
How about using 2 channels of the amp to power the components and then bridge the other 2 to power a sub?
So stay around 1,200 watts and you should be fine right? I would think there is plenty of room to work. A set of components and a sub. What else do you need?
You could always do something like this.
http://www.alpine-usa.com/US-en/products/product.php?model=PDX-5
Get em cheaper on ebay. I like my pdx's pretty well.
Sealed would be nice in there too. My 12" fi Q sounds great sealed(1.2cf) and is plenty loud and it's in the back of my 4 door blazer.
They recommend at least 1.8cf for ported. Check it out here.
http://www.soundsolutionsaudio.com/forum/index.php?showtopic=7155
Does shape matter on a sealed enclosure? Or is the only thing that matters air space?
I'm building a new box and putting it on the side of my blazer, that way I can still lay down my seats and have extra room, etc...
Here is basically what I'm copying...