I’d recommend using distro you know best and/or most prefer to work with. I use the flatpak install of Jellyfin Media Player but there are also deb files available.
I’m currently using minipc with Intel n5105 (or something similar) for 1080p HTPC. Debian 12 OS with auto-login & Jellyfin Media Player starting at login. I control it with pepper jobs RF remote but also have a logitech wireless keyboard+touchpad for it. Keyboard+touchpad come in handy when browsing media sites on firefox but some might restrict quality. Some of the newer minipc’s I tried required adding backports repo to install newer kernel for wifi to work. I had been playing with Debian a lot when I set up first one & been using clonezilla to image them so it’s stuck.
Ordered a gmtek n97 minipc to play with and should have it in about a week. Going to test it out with 4k but it’s not a deal breaker for me if it cannot handle that well enough.