Enterprise, not Green, and not sure you want 3TB as those tend to be mostly slower or variable Green models.
WD / Hitachi / Seagate
You need 2TB or larger drive though for backups now so that you can clone and backup and 3TB gives you room to grow, but not for your array.
4 x 2TB WD Black would probably be a good choice for the array. Then 3-4TB drive(s) for backup purpose.
I bought a 3TB Seagate Barracuda 7200RPM w64MB cache and am using it for backups. No problems yet, but "any drive can fail at any time."
It is 6GB/sec capable, but it seemed to drop back to whatever the external enclosure requires, and connect via FireWire without incident.
I always erase with security Options, write Zeroes, one pass, before I deploy a new drive or re-purpose an older drive.