Audio Concepts at Preston and Forest and audioconceptsonline.com They are relatively new to HT ( a couple years or so), so they still lean towards stereo.
I have found this store to be the best in Dallas.
If you go to Stereo East, you will see Hillcrest Hi-Fidelity. Besides a couple of brands they have nothing to offer in the way of audio. Mostly a custom mid-fi HT installer. I am pretty sure there is another one in the vacinity, but can't remember the name. Anyways, they're all right there, across from the mall, except Audio Concepts which is just a little further south. Have fun.