If you're really feeling adventurous you could relocate the power connector to the other end of the board so that all the cables are connected to one end. Reducing clutter, and allowing for a somewhat larger fan to be mounted on the one end to blow air through both units. Check out post 596 on page 30. Sorry the pics are so big, took them with my phone and it creates huge pics. One of these days I'll resize them.
Yeah was thinking about that to go with the 3" hole and extra 80mm fan.
The 40mm fans work great but now my office sounds like a server room.
Starting to think oil is the way to go...