I am a little confused about your question, but your fans need to be mounted on either side of your radiator, or both. If you have a lot of fans, then I would suggest going with a "push/pull" configuration. This is where you have fans on both sides of the radiator and one fan pushes air through the rad while the fan on the other side of the rad pulls air through. It will help increase airflow on your radiator.
As for optimal airflow, that really depends on the case. But it is most common to have the intake fans at the front and bottom of the case and exhaust fans at the top and rear. The reason for this is because hot air rises. So the air you will be exhausting has been heated. So your PC will cool better if you do not try to defy the laws of physics.
Phanteks makes great cases by the way. I don't have the eclipse, but I have a ethoo luxe and it is very well made.