Here's my setup:
WDTV Live Plus
Thecus N5200Pro NAS enclosure
5x1.5TB Seagate 7200.11 HDDs
The NAS enclosure supports Wake On LAN so I could power it down if I want. Also it forces graceful shutdown.
If you're gonna go NAS, go NAS right. Those 2 drive models are in my opinion a waste of money. Get your own enclosure, get some drives, and put it together. Or find an old case and build one using one of the many applications out there (FreeNAS, openFiler, etc).