Or a 15-L7, be kinda underpowered, but **** it will play loud enough, just sound like a cone full of smashed assholes.
Or try them new woofers from Crunch, like 100 each for 12 or 15, d4/d2/d1 offerings. The guy at the local shop got 4 of them off of 1000d m-class memphis each, and they are retarded loud. Sealed BTW.