Re: CAT 5 or CAT 6 for HDMI?
A "balun" is an old term for a transformer used to "balance" an analog audio or video signal. Unfortunately people still use it to describe media converters that convert digital signals from one format to another (usually to Cat5/6 or fiber). It's kind of like calling a sham-wow a paper towel.
Anyway, we haven't had very good luck with KeyDigital (or Gefen). The Lumagen and Ethereal products have been pretty reliable, but they aren't cheap.
I'd be very suspicious of a 1.4-rated 50' HDMI cable that was under $150. I've seen some that cost 3-5x as much that didn't function properly and none under $250 that produced a usable picture at all. More power to you if it works, especially if it lasts for more than a couple of months.