Thanks for some great feedback folks
That Coolermaster is looking good, I had the first Cosmos, and then went on to a ATCs 840, which is what I have now.
Lovely cases to build in, especially the 840, because the entire motherboard is on a ball bearing track, so you just unplug it, and pull it right out.
So in a way, I'm upscaling my monitor, I just got a 34" 2560x1440 BenQ, (which is a great idea for a panel, it's, it's, native resolution), but downsizing on my pc.
This rig, I have now, was a midrange attempt at a gaming rig, then, I realised, I didn't really like gaming very much. I was more awed by the realism, and graphics, and used to regularly get killed whilst enjoying the view.
So. I'm a photographer. The new monitor plays into that. It calibrates into true colour very well. It's also good for watching movies, and TV. The viewing angles on this new type of panel are nearly as good as IPS.
So I need an averagely powerful pc, mid range GPU (for the resolution), and less all round power than I have now.
I think Turboman has thought deeply about ventilation, and I think I will go with his approach. I'd thought of putting the two Noctua fans in the front, and leaving the Fractal 140 as the only exhaust.
I thought maybe the two 120mm Noctuas might force their way through 4 HDDs spaced out in the 5 drive caddy, (I'm also putting a 120 M2 SSD behind the mobo, for a boot drive), because they have more static pressure than just one 140mm Fractal fan would, and leaving the rear Fractal where it is, what do you think?
All this only becomes more important, and more doable, in a small, closely engineered case, like the R5.
It's designed to be a pretty closed environment, to contain noise, so the gaps are less, also, there is insulative foam, like thick bitumen. on the inner panels. This helps deaden the noise, especially in the non- windowed version I'm getting, but also helps seal the box more.
Creating positive pressure in the case means there is more air blowing in, than out. So every gap, and hole has air coming out of it. So, cool case, no dust. Hopefully :-)
So, I'm getting a midrange ASUS mobo, a Core i5 running at 3.6GHz (no OC), an EVGA 9650 GTX GPU. 8 GB of Corsair RAM, and a 750 watt Corsair PSU, all in the R5 case.
I think I've overspecced the GPU, I reckon I could have got away with a 750 GTX, may be I should have spent that on RAM.
Anyway, we shall see, thank you for your contributions J.