Good shout on the 16GB. Seems more and more games require more and the CPU should be sweet at those clocks.
I would look at either of these, purely for warranty and price.
https://www.overclockers.co.uk/showproduct.php?prodid=GX-289-MS&groupid=701&catid=56&subcat=3059
Free game with that as well (Civilization Beyond Earth).
Or
https://www.overclockers.co.uk/showproduct.php?prodid=GX-071-ZT&groupid=701&catid=1914&subcat=1010
I like your calls, but the 390 is £39 less than the 390X I was eyeing, with a worse cooler. Is it REALLY not worth the £39 for it?
5 year warranty with that and a free game also (Assassin's Creed Syndicate or Rainbow 6 Siege).
Either of those will do you well and both are as good as each other. If you just want to game and do nothing else, I would grab the 390 or if you like to do other things like record your game footage, stream live to twitch or Youtube, have software automatically configure the optimum settings for you in games and have the potential to run 5K on your 2560x1440 screen if you so wish (5120x2880).