another way to reduce fan noise is to reduce the speed of the fan. one of my recent projects is a fan controller with speed proportional to temperature, with the temp sensor wherever you like. see:
http://www.w1ghz.org/small_proj/small_proj.htm I've recently had some PC boards made for this and some of my other small projects, like a Handheld Network Analyzer (and the SDR-1000 makes a great synthesized signal generator to drive it). some of you who enjoy the smell of solder and rosin might be interested in some of these little projects, and I try to make the boards available at low cost. 73 paul