My buddy got the white variant of this case, and I got jealous because my previous case didn't have tempered glass.. So I decided to rebuilt my system into this case.. The P400 doesn't support a top mount rad, so I made a couple modifications - I made a bracket to offset the radiator closer to the side panel. The ram was barely able to fit, since it's so tall..But I made it work.
I had to space out the 280mm radiator in the front with a couple fans, so I didn't really have a choice of whether I wanted to run push/pull or not. Thankfully I had some extra fans lying around.. But the 1080 doesn't go above 35C under load, so I'm pretty happy about that. :)
EDIT* I'm someone who just isn't a fan of aircoolers. I've built numerous pcs, and the moment i switched to AIOs, I started disregarding the aesthetics of air coolers. That's just preferential, and solely aesthetically. I just love them rads!
A majority of people are pointing out the lack of necessity to run an AIO on the 8400 i5. I completely agree with those statements, wholeheartedly. The cost of the aio would have been better spent on a 8600k with an air cooler - without a doubt. However: I was lucky enough to obtain both of my AIOs second hand, as well as my 8400 i5 - in mint condition. I got a fantastic deal on all of those parts, and do not regret my choices one bit. There's no way that I could get an 8600k and an and cooler for the price I paid for all 3 of those.
As for the mod itself, it was the most simple solution I could think of, without having to modify the case itself. I just got metal brackets.. about 2" long, and attached them to the radiator mounting holes. By doing this I offset the mounting holes by which the radiator attaches to the case, so it was pushed closer to the side panel. Keep in mind, the radiator gets pushed slightly outside of the ventilation up top, this could be a slight limiting factor in terms of cooling. I will post up more pics when I get home later tonight! Frankly I wasn't expecting much response. :)
Thanks for checking it out guys! I appreciate the criticism.