After some deliberation I've gone with the Phanteks Enthoo Pro. I like its upgradeability, its clearance, and how 140mm fans can be used everywhere for some hopefully quieter cooling. I shouldn't have to buy a case again for a long, long time!
So far we have:-
Windows 8.1
Intel i5-2500k (3.3 not O/Cd)
8GB DDR3 1600MHz
ASUS P8Z77-V LK
Gigabyte R9 270
1TB HDD
Panteks Enthoo Pro
As the system runs Rome 2 on max settings with absolutely no lag I won't be needing a water cooler of any sort quite yet either