Really the Fractal Design MIDI ARC2 Case can handle 2x280x60x140mm Rads and 9x's 140mm Noctua Fans plus what ever you want in the bottom if you extent the legs.
I running 3 Pumps but thinking about using 2 in 2 Loops - One for the CPU and the other through the X-Fire 290X's - Both through 280x60x140 Coolgate rads in push/pull.
I'm thinking the Corsair H110 will fail.
The Koolance RP 401x's 2 is a great product.
You might think I'm dyslectic an 1/2 blind - Which I'm am.
You can actually run a 280x60x140 rad on top with single fans but you will loose the top 5.25 bay.
Excuse my references to product ID as I' can't remember all labels without taking the time - But if your an enthusiast, you will get my drift.
You can mount a 360X60X120 or a 420x60x140mm rad in push/pull on top but you will loose that 5.25" Optic Bay.
It's all a trade-off. "Do I want to do the dremeling or sheet-metal work?" "Would I ever have need for 'optical drive expansion'" or "Could I use a slimline optical drive." Or would I be happy needing occasionally to plug in an external USB optical drive?
Like I'd said somewhere -- they design the heatpipe coolers to fit in "most cases" and without causing problems for expansion slots or RAM. I barely got my RipJaws "GBRL" heatspreaders to fit under my NH-D14 -- tight fit, but I did it without any "modding."
The watercooling "problem" sits in a nexus of the case design, chosen cooling capacity and radiator sizes and shapes. If one wants a certain cooling capacity requiring a bigger radiator or radiators in series, then you take time to choose the case toward that end, and anticipate some sheet-metal and other fiddling even if you deemed the case to be "near-perfect" for that function.
No getting away from it. And on the air-cooled side of the options? If you buy an NH-D15, you DO expect to lose a PCI-E x1 slot!!