Can someone reccomend a relatively large-scale retail shop where I could shop and buy a HDTV antenna? Not a set-top/indoor unit, but a root/attic antenna. I see a bunch online, but the S&H charges are insane for the lager ones. Radio shack says they have them, but none of the retail stores near me stock them. Walmart doesnt have them. Can someone reccomend a place to look?