Kenwood amp/sub/box "all in one"
Never heard a unit like this, but it "seems" like it would sound good. Maybe others can comment.
For $200 w/ shipping, that gives you everything you need "bass" wise and might be the best idea for someone with your level of audio experience.
Here's what crutchfield has to say about it:
crutchfield review

Kicker 10" sub (you'd need an amp if you go this route)
fosgate sub/box (again, you'll need the amp)
soundstream sub/box really cheap (again, need the amp)