Kevin,
Im in Plano and I have a Radio Shack VU-120XR http://www.radioshack.com/searchsku.asp?find=15-2154 mounted on a 25ft pole. I do have apartments behind my house, so I have to get over them, so you may not need to go so high.
I had a guy named Topp Robertson out to do a site survey. He can tell you exactly where to put your antenna, how high it should be, etc. He charges $50 for a site survey and I think it was well worth it. He also made some adjustments to my dish for the same price. I was receiving all channels except WFAA. Topp came out and after his survey, he told me to either raise my antenna or try an amplifier. Five more feet on my antenna mast and I now get all DT channels. If you arent a DIYer, he can also do the install for you.
Here is his contact info:
Topp Robertson, Owner
Applied Digital Science, LLC
1832 Chaparral Court
Grapevine, Texas 76051-4828
Phone: 817-329-0962
E-mail: info@idigscience.com
I was kind of sold on him once I saw his HDTV antenna setup: http://www.anwireless.com/tx1.html
Hope this helps.