If you’re feeling adventurous, you could cut your front panel audio wires and connect them to a new 3.5mm jack inside the case. It might be a lil janky but it would get the job done for <$10
AudioQuest Dragonfly wouldn’t be a bad way to go. I have a Red on my PC because the onboard mobo audio picks up USB noise. I’ve also got a Cobalt for my phone/headphones. They have a firmware update utility for the Red/Black that you manually install and can uninstall afterwards, the Cobalt ships with current FW and hasn’t been updated yet. That said, they’re pretty expensive for what they are and I got both of mine 50+% off. If you’re considering a “proper” audio setup, I’d go straight to to the Denon unit you’re looking at
There’s a plugin for Jellyfin that will analyze the audio of your content to automatically tag intros, recaps, and credits