In general you only need the front intake and rear exhaust fans. For better air flow you can add top fans too. When you put your cooler in, have it blowing air towards the back exhaust fan to get rid of the heat from your case.
If you are really worried about temps, you could drop down to the Cooler Master HAF line, spend 50 bucks or so for a 912 and buy some fans for it. Not quite as nice as the Define, but not a bad enclosure at all.