Cheers, what would I use to cool the cpu? Would a h80 be ok?
Here's the thing, you could try it and see how it goes with temps in general (not just the CPU), and if it doesn't work out you could quickly try and re-sell it for £5 or £10 quid less than purchase price.
But in theory it's going to affect other parts negatively, given the small size of the case and where you intend to place it. And a non-overclockable CPU like that would be sufficiently (not great but enough) cooled by even the stock Intel cooler.
Also, I might be wrong but I don't reckon a 120mm water cooler like the H80 will fit in the front unless you fit it sideways. Have to bear into account the hoses and rad extending a few cm beyond the size of the fan itself. You'd have to find out. If it doesn't fit sideways, you'd have to remove the optical bay. And I can't see where else you could fit it, for sure, in that case.
I actually think the main issue will mostly be video card temps and motherboard (e.g. VRM's) temps. The 120mm rad on the H80 will lessen the air intake through the front of the case (more obstruction), as well as heat up the air inside the case a little more (by pushing the radiator heat inside it). Using the H80 fan in exhaust (pushing the hot air inside the case out through the rad) might be an even worse idea, because you could end up with bad overall temps
and CPU temp.
It could work though, and if you have a hunch, go for it. I'd probably go for a good low-profile air cooler to be sure. That would leave the front fan more unblocked to intake cool air, and a slim 140mm fan would cool the CPU and mobo at the same time, sufficiently, together with the help of the 80mm side fan on the right (if it has enough room alongside it in the cabinet to do an effective job).
Whatever you do, don't focus on the cooling of just one component, to the detriment of others. The trick with this small case if you're going to use it for gaming will be to bring temps down in general just enough so none of them exceed recommended limits.
Just my opinion.
All that said, my recommendation is a good low-profile heatsink with a slim 140mm fan that has 120mm screwholes to fit on the sink:
YOUR BASKET
1 x
Prolimatech Samuel 17 CPU Cooler £34.99
1 x
Raijintek Aelous Alpha 140mm - Black / Black £7.99
Total : £48.96 (includes shipping : £4.98).
Note: - Maximum CPU cooler height: 65 mm
I just did a quick check with a 140mm fan and an ITX mobo (MSI Z87I) I've got here, and the 140mm fits within the mobo area and doesn't touch the GPU. The layout of this mobo and the one in your basket is practically identical so using a 140mm for added benefits should be no problem.
But I would first experiment attaching all the cables that need to go into the mobo, to see what the best direction to position the heatsink/fan is, so that the fan doesn't press down on any. And ideally, the ends of the heatpipes should point to the back of the case so the PSU fan can extract the heat they dissipate. That sometimes isn't possible though, but it won't affect too much if positioned differently.
Whatever you decide on, I hope you will post pics of your build. You've made me curious to see how it will all turn out.
Alternative fan:
YOUR BASKET
1 x
Prolimatech Ultra Sleek Vortex Fan - 140mm £14.99
An equivalent Radeon would give better performance for BF4 at least but they are just about neck and neck really. 