Crutchfield: What you need to know about HDMI ARC and eARC: How to connect your TV to your receiver or sound bar
Crutchfield is a long-time mail-order seller of audio and video equipment, so their ads might try to "steer" you to their cables. Still, the article appears to be informative.
Optical cables can support very long distances. The CNET article mentioned that some supported distances of over 100 meters (330 feet). The fiber-optic part of such a cable is immune to electrical interference (whereas with normal cables, you'd want to be sure to pick a well-shielded cable to...
TechHive – 4K HDMI cables: How to cut through the marketing lingo and figure out what you actually need
CNET – Best HDMI cables for your new 4K and HDR TV in 2020
Amazon has more "50-foot 4K HDMI cables" than you can shake a stick at, but I think there at at least two things you may want to...