I have ~ 100 high resolution music files (96/24, 88/24, 48/24) which unfortunately cannot be downloaded to my iPhone or iPad. The files were purchased from HDtracks and similar sites.

Normally I play these files with my computer audio or strean them to my HiFi system with a Sqeeze Box Touch

I would like to convert these files to (44/16) ALAC format to listen them on the go in my iPhone

Which software or method do you recommend to get the best possible sound?

Of course I want to keep also the originals in my iTunes library, so I would change the name of the album

Thanks for any advice