If you are concerned with data loss and available space is not as important then go with RAID1 mirror, if you want to maximize drive space and have data loss protection then why not just add a 3rd drive and go with RAID5? Span or RAID0 is only great if you are after performance and have a place...
Yes and no, you can use black and even green but the issue with being kicked out of a RAID array is due to Time Limited Error Recovery (TLER) being disabled. TLER is a feature available on Western Digital's premium, higher-priced range of RAID enabled drives, and can be enabled on green/black...