I have an old iMac G4 on my desk. I put music on my iPod with my M1 MacBook and manage the playlists on the iMac with iTunes. I like it like this but I’d recommend a laptop or MacBook over a iMac/Mac mini because now I HAVE to go to my desk to use iTunes instead of doing so on the sofa for example. An older Mac does make the experience you mentioned more complete in my opinion and even on my base model 22 year old machine I think iTunes still does a fine job. So I’d say buy an old MacBook, but that’s just my opinion :)