Hello there NeilFX,
Just keep in mind that if you plan to use your computer as a sharing device, it should be always on and working. This will put more pressure on the drives, no matter whether you get 2x1TB or 1x2TB WD Blues. Furthermore, these are not NAS specific drives and are not designed for 24/7 activity.
Just because of these reasons, I think that the My Cloud will fit your purposes better. It is streaming no matter whether the PC is on or off. Also, it comes with a Red drive which is generally more reliable for NAS environments.
In case you decide to go with the WD My Cloud, I would suggest you to just set some scheduled back ups to your PC and thus keep your data safe.
Hope this clarified the things a bit,
D_Know_WD