I used subwoofertools to come up with this plan. Driver displacement is 0 because I plan on mounting inverted (Will mounting inverted make a difference in SQ or SPL?) The box must be 15.25" high and 29" wide, externally. ID suggested 2.55 cubes tuned to 28hz. Plugging that data in and a few more from ID's spec sheet gave me this:
Am I good to go?