I recommend try a Winegard MS2002 omnidirectional antenna. Please note that omnidirectional antennas are not 100% omnidirectional the antenna will likley need to be turned to find a spot that receives tv stations to the , north , west and south and then tighten the clamps. Here are places to buy tv antennas and etc. ,
http://www.solidsignal.com ,
http://www.amazon.com. If you need some one to install you can try
http://www.zipinstallation.com