Up here Radio Shack is now called "The Source" due to some legal difficulty.... Circuit City bought the Canadian RS......

Pop over to your public library and have a look at the radio amateurs handbook.... if your handy with tools there are lots of antennas in there you could build yourself.

Out door antennas on a house are not really hard to set up. You could start with one on a deck rail for instance and move it up to the roof later. You just have to be able to run a wire from the TV outside. Home Depot will sell you the RG59 cable already to go... just buy the length you need.