For those of you, who want to use water cooling on Cosmos II I have following suggestion.
You can put the radiator inside top, and the fans outside top. Now the problem is, 25 mm thick fans can give you clearance problems. I experienced this with my Rampage IV Extreme. These fans of Scythe ("SLIP STREAM SLIM" 120 x 12mm Fan) are 12 mm thick and would fit inside top w/o any problems. I'm ordering mine on Monday. Just wanted to give you guys a heads up as everyone on different forums is complaining about not being able to use fans inside to pull and outside to push. I hope the solution helps.