We have done several OTA installs and we just give Denny's antenna service and use their recommendation. We have some installs in attics, some that needed two antennas facing different directions to get all the channels, etc. I have their small EZ HDTV antenna on my house and it works great. Their recommendations on which stations we should be able to receive have been spot on. Worth a call.
http://dennysantennaservice.com/