optimal power for the mids is 200 watts if you will be using eq. You reach xmax at 50hz and be -12db. These are very efficient though so you could almost definitely add 12db of boost keeping flat frequency response to 50hz or lower depending on you're desired SPL.

using the dcx2496 as your xover you can tailor the response to anything you like though as long as you go with a sealed box. So you could make it not as deep if you needed to, keeping in mind it will require more eq down low to get the same response.

Again these are just suggestions from my experience with these mids and tweeters. Going with a sealed box, enough pt2's, those mids, and a good xover like the 2496 it will be hard to go wrong.