I just got a Technics SA-C600 and some Dali Oberon 5 speakers. My music collection is on compact disc, but having been imported into iTunes is all in .mp3 or .m4a format. Obviously I don't want to listen to this format, so I am faced with re-importing all of my music into a new library. Which software would everyone recommend I use ? I want to store all of it on an external hard drive that I can use as as a backup and also to listen off the Technics app on my phone when I'm out and about. Suggestions?