What is my best option? Do I rip all of them on my iMac through iTunes and then sign up for iTunes Match to get all of them into my iCloud?
Why exactly do you want to get rid of the CDs? If it's about room, I'd just rip them and keep two backups. If you think you may convert them to a yet unknown format in the future, you can use the ALAC (Apple lossless) format (100 CDs would take somewhere between 30 and 60 GB, which would even fit on a USB stick). Otherwise I'd recommend 256kbps AAC (which would probably take between 16 and 30 GB).
If I already have Apple Music, is iTunes Match included?
Yes.
Doesn't iTunes Match permanently match up your ripped collection with the iTunes library if both albums are available? Like if I rip a Beatles album and it matches with the iTunes version so I get it saved in the cloud as I own it?
Two things to be aware of:
- Once the subscription ends, you lose access to your songs
- iTunes Match/Apple Music is *not* a backup solution. The matching process isn't perfect and sometimes matches to a wrong song or a different version of a song. For example, I have the Beatles in Mono collection and Apple Music has matched some of the songs to the stereo versions. So don't just rely on the cloud. If you rip your CDs, keep backups of the original files.
So technically if you only buy mainstream music, and all the albums are available on iTunes, I only need to "match" it once?
If you have Apple Music, you may find that you end up not using your own rips at all, since Apple will probably have most your albums already. You can just as well find the albums by browsing Apple Music and add them to your library with a single click if you want to. Perhaps something to consider before you start ripping 100 discs just for the purpose of matching.