There is probably no good reason to have music files that exceed redbook. If you google around, there is a lot on this subject and, like with all things dealing with music, no end of disagreement.
Why Neil Young's New Pono Music Player Doesn't Make Any Sense I'm skeptical that there is any reason to listen to hi res (higher than redbook) music files. There can also be real headaches involved in getting a system to work that plays those kinds of files.
Once you settle on lossless (flac or alac) or high quality MP3s as your formats (because they sound really, really good and there is no good reason to pay for uber expensive high resolution music files), then finding the files you need is a piece of cake. Either rip your CDs or buy your music from Amazon, iTunes, etc. Or ditch owning media and just rent your music from MOG, Spotify, etc.