This is very similar to what the British comedian James Acaster does/did. He buys music off Bandcamp then puts it on his iPod. He documented it all in his second book Perfect Sound Whatever, it helped him get over a breakup and depression around 2016 if I remember right. He jokes in his book that he has an 'iPod guy' who hooks him up with the old iPods. His recommendations here:
https://www.jamesacaster.com/my-music/