there's a lot of good brands out there, kicker, JL audio, mtx, rockford fosgate, etc. You could definately find something for under $400 that would make you happy. Good amp 200, nice sub 125, that's only 325. About the box, the bandpass box will be louder, but the sealed box will have a little bit better sound quality. I don't think you'd even notice the difference in sound quality much at all, so I'd recommend a bandpass box for you, it would be much boomier.
