Thanks for all of your contributions! I learned some things.
Some notes:
- I was in fact thinking of HDMI-over-twisted-pair rather than HDMI-over-Ethernet
- In hindsight, I don't really want to have to plug in more powered devices to accomplish my goal and for <= 50' probably passive cable is the way to go
- Curse you, Adam, for reminding me about Princess Auto; now there are suddenly 5 things on my shopping list
- Oh well - my birthday is coming up
- Princess Auto's 50' HDMI cable is rated for HDMI 2.0, which should be more than good enough for my need