I have the same case and I have a BitFenix Spectre Pro 200mm Fan installed on top. The only place I was able to find it was on amazon.http://www.amazon.com/gp/product/B007OWPM8W/ref=oh_details_o00_s01_i00?ie=UTF8&psc=1
Go to http://pcpartpicker.com/b/Dd3
and see for yourself. In the fifth, sixth, and the last picture are shots of the BitFenix fan to give you an idea what it will look at inside the HAF XB.