PS. If you want to know what content is available "over the air" in your neighborhood a web location
www.titantv.com is the new version of the TV Guide. Enter your lcoation and choose over the air and you will see all the OTA content. Note that depending on tower location you might not be able to get ALL of them from one antenna. Hopefully your MR Antenna kind of supplier will be able to tell you what you can get from your location.
I also found a "Tv Tower Locator" that can help, you put in your zip (and in some cases, down to your address so it can get a precise GPS location) and can tell you what coverage you MIGHT get. It's not precise but it's a good start.