I was interested in purchasing the BL 12 subwoofer with all additional options. I currently drive a Honda Civic 2 door and don't have a lot of trunk space to work with, specifically 16" height X 32" depth X 30"+ inches of width. I wanted to know what the smallest possible enclosure dimensions could be for a ported box, with the box tuned at 33 hz with roughly 2 cubic feet. I am planning on running a Kenwood X1200M, which is 1200 watts @ 2 ohms, which should be sufficient for the sub, right? Also, is there an advantage in running my sub at 2 ohms instead of 1? Specific dimensions and instructions would be appreciated as I am a rookie in the field of car audio. Thanks.

That amp will do fine. The only reason there are different impedance is for matching amplifiers to subwoofers. In order to wire to that Kenwood you will need a D1 woofer.