If you decide to go with the 2 separate antenna solution with 2 separate down leads then saveandreplay ,
http://www.saveandreplay.com has remote control A/B antenna switches. Also read and understand this about , Real Broadcast Digital Tv Channels , Virtual Broadcast Digital Tv Channels , Analog Tv Channels ,
http://forum.tvfool.com/showthread.php?t=695 .