[lug] what makes a good cpu fan?

[D. Stimits]

I'm wondering what makes a cpu fan the most reliable? Is it brushless 
design? Is it a ball bearing design? This might not matter, because I'm 
searching for a replacement on an old Pentium 1 MMX 166. The machine 
runs 24/7, and has not had a part failure ever in many years (it is 
beyond what many would consider its life expectancy, but it is a very 
nice firewall/bridge, and the cpu can almost survive even without a 
heatsink).

Secondarily, where would people buy a good (old) heatsink/fan combo for 
the old Pentium 1?

D. Stimits, stimits AT attbi DOT com