1-2w ?How much electricity does a fan that size really take?
Those fans don't use more than 2watts.
I don't see being able to run a Pentium 3 fanless unless it is a pretty large heatsink setup -- which would be expensive. You can reduce the fan speed (and wattage use) by getting a Zalman Fanmate 2 controller for about $7-8. It has a variable control and can be adjusted to run the fan pretty slow -- makes the fan nice and quiet too. Used one with my Celeron-T CPU for years.
Is it socket 370 or Slot 1 you need?
is it on the board? or is it on a slot and vertical from it?
http://images.yourdictionary.com/slot-1