try checking the data sheets.
madge
i beleive they take care of Olicom hardware.
You'll need to know how hot it gets the way you have it set up.
you should also take the cover off and see how much room is in there, you may be able to come up with other ideas than simply changing 60mm fans. Mybe a couple of low profils 80mm with some simple ducting sucking the warm air through the top. Don't know your set up so...