Go to newegg.com. Look at these items:http://www.newegg.com/Store/SubCategory.aspx?SubCategory=572&name=Memory-Chipset-Cooling
You may need to dig a bit through the many fans/heatsinks for something that will fit your mobo. BTW, what make and model of mobo are you using?
Any fan that will directly blow cooler air onto your chipset will help. Looking at the other post, however, I would assume you have a faulty sensor. Try this app to see what it reports:http://www.piriform.com/speccy
Easy to use, free, no malware, and will report a fair amount of system info.