Whats the details on the car?
What alternator?
What size wiring in the big 3?
What size power wire you running?
How much money you got to spend?
You are getting into an area thats going to require a high output alternator, ample wiring and quite possibly a secondary battery in the back. Total cost on these items will set you back a minimum of $500 upwards $1,000 or more.
I would advise against the JL. The basic answer is because its a single 3 Ohm coil. So you want about 750 WRMS @ 3 ohms. That alone is NOT cheap and finding something rated like that is impossible... So you would want 1000 WRMS @ 4 ohms... To be comparable.
Heres some other options:
http://www.sundownaudio.com/index.ph...tshade-12.html
http://dcsoundlab.com/woofers.html
DC Lvl 4
http://www.audioque.com/aq/?page_id=24
https://ssl.perfora.net/www.ficaraud...iew.shopscript
Fi BL 12
http://americanbassusa.com/front/sho...spx?fileid=225
American bass HD12, I sell these
http://ascendantaudio.com/havoc.php
Im sure Im missing some other contenders, but I covered most of them!