I got my Stealths and Thermoflows from BigFootComputers a few years ago. I think it was cheaper at SVC but for some reason I didn't order there because they didn't ship to Canada.
(80 mm)
http://www.bigfootcomputers.com/Merc...Category_Code=
(92 mm)
http://www.svcompucycle.com/92vanthertem.html
Here's a quick list of other 92x25mm fans with their ratings:
http://www.svcompucycle.com/standardfans92.html
The Stealths at full speed appear to be rated quieter than the Thermoflows at low speed. Hmmm.
As for temp sensor, I've read before that the wire going to the motherboard is only used to provide the RPM speed to the computer. The computer doesn't control the fan speed.