Hi all, I've got a 24" iMac Core2 Duo 2.4GHz with an internal 320GB HD. I'm thinking of upgrading the internal drive to a WD 2TB Green drive (WD20EARS) (newegg $70). What do you think about that for the internal drive? I'm not a high-power user, just a big music library, some video, occasional video editing, no games. (I'd also like to get an external 2TB drive for backup, if you have any thoughts on that as well) Thanks!