I would keep Shields local to each TV. No reason to co-locate them unless you want to try and "share" one Shield with multiple TV's. If you want to send audio from your Shield back to your audio matrix, you'll need to wire for this as well.
If you want to co-locate a few Cable boxes at your rack, you'll need some type of video distribution. C4 HDMI matrix, JAP, MOIP, etc. For this, you'll need at least one CAT6 run from your rack to each TV to carry the video signal. Presumably, you'll be playing TV audio through the AVR for that zone, or through your Triad AMS.
If you want to co-locate your AVR's in your rack, you'll need to have home-runs from each speaker powered by that AVR back to your rack (so they can be connected to your AVR).
Co-locating game consoles doesn't really make sense most of the time. Most people tend to keep these local due to wireless connectivity between game console controllers and the console themselves.