Can anyone suggest which would be my best option for external backup? Would a RAID setup be good? I have two exactly the same hard drives laying around collecting dust, and would like to put them to use for an iMac. Could someone recommend a good external enclosure for these two? Which would be better - FireWire or USB2.0? I'm also interested in mirroring since I'd store important data on them, and want both drives to have a copy of each. Is there a disadvantage to that in terms of system's performance?