Well.. these guys seem to be the only retailers I could find:
http://www.adpmods.com/xcart/catalog...Fan_41CFM.html
The maker is ARX:
http://www.actrx.com.tw/
(warning, flash website...)
http://www.actrx.com.tw/datasheet/4010.pdf
http://www.actrx.com.tw/datasheet/4020_2.pdf
VS. Delta
http://www.excess-solutions.com/SpecSheets/AFB4010.pdf
http://www.excess-solutions.com/Spec...elta404020.htm
Do a google search on 'ceramic bearing fan reviews' They seem to get favorable reviews, but of course a reviewer cant make any determination of the lifespan of a fan.
I've got at least a dozen 40mm fans in various machines, and almost all of them are replacements. The stupid things only last about 6-12 months. Most fail noisily, which is good, but the silent failures have killed at least one hard drive.