Just be advised that an NAS drive is a risky beast to manage. I used a WD My Cloud drive for Time Machine backup and the initial installation went well. But after a move cross-country, it quite working. Even with exactly the same hardware configured exactly the same way, it refused to work. And from what I could read about the cryptic error message I was getting, the problem is a common one and wouldn't be an easy fix.
If I'd had a USB drive instead, that wouldn't be a problem. So my advice is that, unless you need the drive to be kept too distant for USB to work or you need to back up multiple computers to one drive, don't go with NAS. The risks outweigh the benefits.