if you are still wanting to venture this, go Dual RE8's.
1 cubic foot ported, with a 4inch port on the side and 8inches long.
With around 600wrms on 1ohm load, should see you in the high 130's even into 140's.
Done a setup on one of my cars approx 1 year ago.
managed 140.6db @56hz on rta scale. You will be more than happy with the setup. If you like i can PM you the box specs.
I ended up turning the bass down on the Alpine unit from 11-12 on sealed applications to 3-4 in the dual ported setup. And generally it was still pretty **** loud.