Space for a 300 disc collection ripped to FLAC should not be bad at all. Try looking at MP3 with a much lower BR then 320, as, IMHO that is really overkill for a lossy codec.

You may also want to try dBpoweramp for your ripping. It is at least (maybe more) secure then EAC. R13 will have tagging features that blow anything else out of the water.