that should bump plenty good!

15 inch will be good for lows but you will have to punch to drive any mid tones.

Anyone got a link to a good site where I could buy the amp and/or sub from? The shop quoted me $550 on the amp, and $375 for the 15".... I don't mind the 15" I just dont know if I can drop over a half a G on the amp. Thanks.

BTW, just told my dad about how much money I am planing to put into the car, his reaction: Priceless!

I wouldnt suggest getting a cap. It isnt going to do anything for you. I would put that money torwards a better alt. I would also get a red top battery if you are going to go with Optima. You really dont need a yellow top so there would be more money you would save. I have found the red tops as cheap as a lil under $90 before shipping. Also keep in mind that every part of the system is important. I would always pick performance always over style. You get what you paid for.

Are you referring to any particular part of my decision here... or just a general rule of thumb?

Just like engine mods some things work better with others. Match components well, I'd suggest 1 12w3 or 10w3 even, in a sealed box with a proper amp. Itll be louder then you think. 2 subs is only 3db more then 1 sub.

Why not the 15?

www.purecaraudio.com
I recommend you keep it SIMPLE and just plug and play - no custom ****.
I learned that the hard way, besides , you can be pretty loud with tearing stuff up.
It is a very EXPENSIVE hobby, don't go cheap cause you'll only wind up throwing it away and getting better!

15 is ok for rap and pure SPL, but what kind of music you listen to? What do you want it to do?

I feel this is an important factor to consider, if big bass is your thing, go for the 15. But if you like to be able to hear MUSIC instead of bass, go for a pair of 10s or 12s.