CJ, I highly recommend that you take a trip over to the Stereo Shoppe on W. Stadium. They carry B&W (oldest B&W dealer in the state), Rotel, Phase Tech (my favorite!), Klipsch Reference, Yamaha, and other stuff. Don't let them sell you their expensive Audioquest cables, but they're good people and carry nice stuff.
The other two dealers that I would visit would be Paragon Sight and Sound, and Overture Audio.
For your speakers, you should look for a sealed or front-ported speaker. Rear ported speakers will not work well in a cabinet. Ideally you would keep your speakers freestanding, but that might not work with your aesthetic vision.
The subwoofer is another concern. Subwoofers are very sensitive (like any speaker) to placement. To really get the most out of your subwoofer, you'll need to move it around. Chances are, the place you have picked out for it in the cabinet is not the best place. Secondly, great care must be taken to properly isolate the subwoofer from the cabinet. Thirdly, to get good, theatrical bass, you'll need to use a front-firing sealed design with a boatload of power. This basically equates to buying an HGS or DD series subwoofer from Velodyne, which is quite expensive. The infinite baffle subwoofer is an interesting idea, but I still think that for your purposes the best route would be a free-standing subwoofer from SVS or Hsu. They represent an excellent value and will give you plenty of high-quality bass while leaving you more money to invest in speakers and electronics.