I would use the DB8 , and I agree with GUM , the term multidirectional that is thrown around to discribe Tv antennas is marketing department nonsense. The 8 bay antenna has narrow forward half power beam width. However in your situation this works in your favor. WNED UHF 43 shows possible adjacent channel interference from CITY-DT UHF 44. . So point the narrow beam width , high gain DB8 antenna more in the direction of the American stations that are weaker in signal strength. The Canada stations are Very Strong and I believe will come in quite well at a angle on the antenna. I am thinking that one antenna will do it. Read and understand about , REAL Digital Broadcast Tv Channels , Virtual Digital Broadcast Tv Channels , Analog Broadcast Tv Channels , this is the same in the USA and Canada ,
http://forum.tvfool.com/showthread.php?t=695