whatever you choose for the enclosure, get this driver. You cannot beat in in price/performance. I would also inquire about getting a gasket with it, but they won't supply the speaker gasket, then go to Walmart and pick up the Duck brand rope caulk, the stuff is amazing. It's just the right width and squishes down like clay, air-tight.
I would definitely choose the enclosure flat panel, you will save yourself from having to make bracing for it. The bracing that comes with the enclosure has been CNC cut and fits together perfectly, and believe me, I mean perfectly.