I do this and just run Ubuntu on a Thinkcenter tiny.
Then this for input off the sofa.
I also put a few Braille dots on few buttons and glow in the dark paint on a few important dots to make it more usable which really works, Braille especially.
Then… A few bookmarks in the firefox, jellyfin, navidrome, Spotify, vlc/MPV from mounted NAS etc.
I don’t bother with any media/apps interface, I mostly see them as annoying and not needed with this KB/trackball setup.
Then…Bob’s your uncle!
Thinkcenter tiny, 4 external HDDs, a DAC, a raspi3b+, was like 25W I think.