What are they cooling, the CPU? If so, I'd say have the 240mm rad. on the top as exhaust. And instead of 2 intake fans, place the 120mm fan from the bottom as an exhaust fan at the back.
You generally want more exhaust than intake(negative pressure)
See: http://www.tomshardware.com/faq/id-1858957/airflow-101-setting-fans-keeping-computer-cool.html