Ah, you should have said so in the initial post. My recommendation would have been a little different: to rip in iTunes at the lowest (and fastest) speed, then load up your Mac with all your music and then take advantage of iTunes Match. With an iTunes Match subscription, iTunes matches your library, uploads any unmatched tracks, and makes your music available on multiple devices through the iCloud Music Library, available to all your devices for streaming, without your needing to use storage space on your devices. If you have low-quality tracks, iTunes Match “upgrades” them, allowing you to download 256 kbps AAC files without DRM.
iTunes Match costs $25/yr, and is separate from Apple Music. But if you’re going iOS-only I think the price might be worth it.