My headunit is in place, and I just put in my box. (Downfire, 2 10", made by AE) Here's a picture of the closest thing I can find.
http://www.pickupspecialties.com/Subwoofer_boxes/mustang_dual_subwoofer_enclosure.htm
Now, I just need to decide on a amp/sub setup. I know I want two 10" subs...