Note that while NAS would probably increase the supportability and as a result, probably the reliability of the system, most NAS systems (SMB/CIFS) are going to be considerably slower than locally attached storage (network file system vs. local file system).

Normally, I would say this isn't a big deal, but if he is doing video editing, I'd venture it probably wouldn't be a good move.

In fact, as others have pointed out, for video, probably want to stick with RAID 0 or 1+0 (stripe of mirrors), or have a dedicated scratch space for in progress work which could be a single drive, or RAID 1.

-john