Trusted computing vendor MacSales.com...
View deals + wish lists at B&Photo...
Buy other stuff at Amazon.com...
for 2013 Mac Pro
Free how-to videos and tools included, 3-year warranty
BUY MacBook Pro Retina 16GB / 1TB / Radeon R9
Add a pocket-size 1TB SSD for travel backup + high capacity storage + port connectivity
RAID-1 Mirror in Hardware vs Software
For software mirroring, Apple’s Disk Utility has support built-in.
Hardware RAID-1 mirroring is simple with an external dual-drive enclosure that supports it: set the switch to mirror mode, and it’s ready to go.
Dual-drive hardware RAID-1 is the simplest option because the enclosure itself takes care of the RAID issues, presenting itself to the system as if it were a single drive. Initialize it just as you would any single drive.
Shown below is one dual-drive RAID-1 capable unit, the OWC Mercury Elite Pro Dual (it can also be sued for RAID-0 striping or indepedent drives).
See OWC Dual-drive Enclosures Overview for more ideas of what is available.