If you use the standard intel Sandybidge fan, the HDD mounting bracket will not fit. Then just mount it with Velcro strips. Fan does touch the case and a felt bumper on top will buffer it again any vibration noise.
I am using a Dynatron T459 HSF which will fit under the HDD and mounting bracket. There is a higher CFM model T357 which is a bit louder. Gelid has a low profile HSF too.
My setup is using a 2.5in intel SSD. Intel DH61AG MB has a miniPCIe slot that can take a SSD and eliminate the need for a SATA SSD/HDD. The new DQ77KB is an updated version of the DH61AG.