thanks @crashoverride for taking a shot but the idea behind the MZC-66 system is a multi-source & multi-zone distribution system via cat5 or up. I currently have cat5 distributed from the MZC to multiple zones throughout the house that allow for audio and video to be used anywhere with the sources (ie. cable boxes) in one central location (attached to the MZC).
The issue is how do I go from SD video to HD video through the MZC? If I use the extenders, I am unsure to handle the switching via the MZC. The MZC provides the ability to push video over composite cables but not HDMI nor CAT