Digital streaming/library


I have purchased a rather substantial 2 channel audio system, and two of the components are a streamer and an audio nas...a melco. I want to build a digital music library. I would love to have the hd level tracks, but the downloads are so expensive. I already have thousands of lps, and thousands of cds. I have iTunes, and it (and rhapsody) allow you to download tracks into your computer...but they are not cd quality. I have a streamer, and I could get the tidal or deezer hi res subscriptions, but do they allow you to download tracks into your computer/nas drive for a digital library?
128x128easola01
Perhaps the best program you can use with Windows is free EAC (Exact Audio Copy).  This program will try to go over same unreadable sector more times than ITunes, that eventually will start interpolating or even dropping out samples - big advantage with scratched CDs, not so much with new.  Selecting format to use is another story.  ALAC, that I use, is more of an Apple thing, while FLAC is not supported by Itunes.  Best choice for you might be AIFF because it can hold metadata.  It takes more space than FLAC, but storage is cheap, these days.  Be sure to create backups.  
Okay. I have read that flac is the way to go for metadata and sound quality combined. Is AIFF as good and thorough for metadata as flac do you think? If not, I may have to go another way
AIFF is as good as FLAC but files take roughly twice more space.  ITunes doesn't play FLAC.
Murfie.com has a marketplace where you can buy CDs and download the files from them in FLAC or ALAC. You can't get files with higher resolution than 44.1/16, but it's much cheaper than HDTracks.