Of your choices, go with the increased RAM. A 320Gb will hold around 400 CDs in their native format. If you later out grow the drive you simply copy clone the drive to a larger drive.
At the level of DAC you're considering I think the "upgraded" Mac Mini with the SSD and maxed out RAM is overkill. If I were you I'd get a stock Mini and put the savings somewhere else in my system/music collection.
At the level of DAC you're considering I think the "upgraded" Mac Mini with the SSD and maxed out RAM is overkill. If I were you I'd get a stock Mini and put the savings somewhere else in my system/music collection.