Depending if you want ones with LED or non LED but i would strongly suggest Luna fans, they come with Anti vibration mounting and have awesome airflow
http://www.thermaltakeusa.com/Cooling/Case_Fan_/Luna/C_00002230/Luna_12_LED_White/design.htm
Wow.... lol that thing is actually quite cool lol
i found one on ebay http://www.ebay.com/itm/Thermaltake-Xray-A2021-5-25-Drive-/141442517318?pt=Altre_Schede_per_PC_e_Server&hash=item20eea18946