If you buy NA version, your subscription will be priced in US dollar.
If yours is EU version, subscription will be euro/pound, etc.
NA and EU are sharing the same servers.

PC version for PC only.
PS4 version for PS4.
You cannot use PS4 version on PC and vice versa.
*If you use steam, you can only upgrade through steam.

This post has been edited by Vickyle: Apr 16 2015, 06:19 PM