You are lucky , all the receivable stations are of one direction , about 151 degree magnetic compass. The antenna will be mounted above the roof top on the out side of the roof not in the attic. I suggest a Winegard HD7698P antenna. This antenna will supply signal to up to 4 Tv's. Here are mounts that will not make holes in the roof.
http://www.eham.net/libraries/download/430/Photo_A.jpg , notice the wide spacing of the straps , this makes the antenna stable. And
http://www.sadoun.com/Sat/Products/Perfect/PVEM1.gif