The first links on that page is a 25 foot 30 AWG cable, which is ludicrous. No surprise that the reviews for the item state it doesn't work at 1080p, only lower resolutions. The positive reviews seem to be for a completely different 6-foot cable...
The only 30 foot cable I see there is listed as 28AWG, which is also too thin without some form of active equalization like RedMere...
Suggestion based on what I'm seeing: avoid the cables meritline is selling. The 25-foot 26AWG one they have is probably OK, but it's not long enough if you're looking for 30 feet.