Wow, first of all thank you for the fast responses.
If it's a reliability issue regarding the SSD, that would certainly make sense to swap it to the m4.
The Hyper 212+ is a little more expensive in the UK compared to the Arctic, however it would be a small price to pay for a known, stable...
Well it looks like my last computer is about to bite the big one, and is at the point where a brand new build is my best option. My current experience is a little limited, swapping out graphics cards and RAM and installing a new OS being about the sum total, so apologies in advance for any...