Chevy, I just switched to the Radio Shack model you just mentioned from a Terk TV-55 that I spent 100 bucks on. The radio shack is doing a better job for me. All of my towers are within 8 degrees from each other (compass direction) so a directional Yagi uda antenna does better for me than an omni directional antenna like the TV-55.
My problem was multi-path issues that the Yagi seems to have fixed. I am fairly close to the antennas (about 6.5 miles away) but my line of sight is somewhat obscured by the tops of houses and trees.
I was considering getting an antenna from the following:
http://www.antennasdirect.com/
but I thought I'd give the inexpensive radio shack one a try and I think I'll keep it.
Since you are 40 miles away you may want to consider something like the XG42 from the above listed URL. The gain on it is going to be considerably higher than the radio shack model.