Your reception situation is easy , I recommend a Winegard HD7697P antenna and a Channel Master CM9521A rotor and you will have it All. No preamp needed. Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html. Also I recommend new RG-6 coax from the antenna to the Tv. Here are places to buy antennas and etc. ,
http://www.solidsignal.com ,
http://www.amazon.com ,
http://www.starkelectronic.com ,
http://www.3starinc.com. Here are some antenna mounts ,
http://www.ronard.com/909911.html ,
http://www.ronard.com/34424560.html ,
http://www.ronard.com/ychim.html