I currently have the fans for my radiators as Top 3 x 120mm sucking through the rad. Bottom 3 x 120mm sucking through the rad exhausting through the bottom of the case. I also have 5 X 140mm. 1 exhaust and 4 drawing are into the case. But tomorrow all that changes im getting 2 X 480 rads. (next upgrade) I trying to cool a pair of 980ti's and well as CPU. Would the same fan set up be advisable. Or would I see better cooling if I was to switch the bottom to draw air in? But that would introduce hot air into the case. I know that the top needs to be exhaust. (heat rises and all that) My case is plenty big enough (Phanteks Enthoo Primo)
I'm running 2 GTX980 TI's & CPU with 2x 480mm and a single 140mm Rad. I've got the bottom rad and 2x120mm fans pulling air in and the top/rear exhausting. The temps in my 900D are about the 45-50'c mark on GPU's depending on game etc. at 99%~ load so doing something similar in yours should be fine.
