As long as you use an open source format like FLAC, you're probably not running much of a risk of format obsoleteness. I primarily secure rip to hard disk for archiving anyway. 16-bit FLAC files do not increase in size, hard disk drives do. Making backups of backups of ever increasing collections shouldn't be too much of a financial burden. I would never store in a Cloud.
I switched to an iMac a few years ago (still on Snow Leopard). iTunes does not play FLAC, but VLC does and .cue sheets can be used as playlists easily enough.
As for Windows 8 (or 9, 10 ,11, etc.), I would sooner install Ubuntu on a new PC.