I want to use an OTA HD antenna...

You can go here TV Fool to see what channels are available in your area . It will give you height and the direction calculations in which your antenna needs to be pointed.

I would try Radio Shack for an HD antenna. The basic one is no more than $30 and it will give you great reception. You can always add an amplifier if needed. If you live in a metropolitan area..chances are an amplifier isn't necessary.

From comparing cable HD verses over the air HD..over the air wins hands down! Not sure why, my best guess is because of the compression used by the cable companies. The over the air channels are uncompressed and it doesn't need miles of copper and line amplifiers to reach your home.

You may want to grab your two free $40 coupons for the digital tuner or tuners. $80 saved.. is $80 saved, no matter how you slice it.

I was gonna say what Gmood said, there is not going to be a better signal than over the air reception, cable is cool for budget reasons but for a bit of cash spent once I would do OTA.

I have both Dish and Directv on my roof. I think it's a bling thing. This technology has come a long way from the 12 FOOT dish I had 20 years ago... The audio from satelite destroys cable. Picture, by some margin as well. Dish is now doing PPV in 1080p. Your cable company will NEVER come close to this level of performance. The bandwidth simply does not exsist.
Got an attic?