I appreciate I'm late to the party on this one, but there's a few things to clear up and expand on others.
As far as I'm aware, there's no reason to use WAV (or other uncompressed audio formats) compared to FLAC (or other losslessly compressed audio formats) - they'll both support anything you'll find out in the wild.
For music storage, I've got all of mine stored in Dropbox as well as on my Plex server. It's convenient to stream via Plexamp and I use Foobar2000 on my PC (Tek Syndicate has a video on how to set it up efficiently, it's old but it does the job - if you follow it there's a new and improved lyric plugin that you should use instead).
I personally much prefer using it compared to streaming, having lyrics and whatnot displayed nicely in the player is so much nicer than Spotify, and using ReplayGain is a much better approach than normalisation for consistent levels between songs. It's not for everyone, but if you can hear the difference I'd highly recommended getting it setup.
As for acquiring music, I buy CDs and rip them through ExactAudioCopy for bands I care about and acquire others through "other" means. I've not had problems with EPs and singles, places like Qobuz and 7Digital tend to have them when they're released.
The storage need isn't excessive really, I've got plenty of music saved and it's about 700GB I think. Especially if you put it on a hard drive it's nothing nowadays.