Bazooka Tube!

Ok, I figured this would be the place to turn to for this question. I'm not familiar with audio systems at all, but I really want some more bass added to my stock (EX) stereo setup. So far here's what I'm thinking.

-The stock HU is integrated with the HVAC controls which makes replacing it with an aftermarket HU a pain. I've seen the Metra dash kit and truly hate how it looks, plus all the added expense it incurs. I want to keep my STOCK HU. I know this will limit my sound quality, but i'm not making a show car - I just want some more bass. I might add better speakers at a later date in the stock location.

-I don't want or need a HUGE amount of bass. A friend of mine has an E46 sedan with two 12's hooked up to a 600w amp. This is way too much (both in consumed trunk space as well as crazy bass. Don't need/want that much.)

Here's what I'm thinking:

-8" pre-amped bazooka tube. They make decent bass, they're tiny, and you have a lot of options for where to put them. I want a pre-amped one for space and simplicity; if i get a different car I can just unhook it and go. I'm thinking it'll go in the front of the trunk facing rearwards for sound dispersion.

however, what I want to know is, what else do I need?

I know Bazooka makes quick-connect kits for stock head units, but they're a little sparse on the details. I've also heard about other setups - like the BassLink? Really don't know much about this stuff.

I know I'll need a power cord run to the positive battery terminal with a big fuse in line. I also know I'll need something to interface the sub with the head unit. If it's hooked up in this manner will I be able to control the sub seperately from the speakers? Ideally i'd link to crank the bass down on the speakers and up on the sub, but if it's hooked in like this I don't know how.

Sorry for the "noob level" audio question. I'm more of a gears and wrenches type. Any help as to what else I"d need to hook a pre-amped sub up to my stock audio system would be great, or if there's a better pre-amped sub or solution I haven't thought of (that doesn't include replacing the factory HU) I'm all ears. Thanks guys!