My old Blizzard060/PCC is only overclocked to 60MHz but it's been running fine now for the past 6 or 7 years with just a wee 40x40x8mm 12V fan from Maplins fixed to it with some sticky fixers, never had a problem with it at all...
You can buy these wee fans for a couple of quid from Maplins and they run very quietly...
