I have about 2TB of music files and use Tidal/Qobuz for streaming. The music files are for albums not in Tidal/Qobuz. I currently use Roon and HQ Player with a mini-PC, but the mini-pc may be dead.
If it is, would it be possible to replace it with a WiiM ultra streamer?
If so, where would I install Roon and use it with the WIIM?
The WiiM Ultra is just a Roon Ready streamer (and amp etc), i.e., an audio output as far as Roon is concerned. You still need to run a Roon Server somewhere.