markjs,
I've had really good luck with
this one. I'm using it on an AMD 2500+ Barton (11X200, 3200+) and in a 70F (21C) room it idles @ 93F (34C) and max out @ 104F (40C) under 100% CPU load using Arctic Silver 5. I used the same HSF on an AMD 1700+ DLT3C 0307 @ 11X200 and got almost the same temps the short time the 1700+ was in at those speeds.
The other thing I like about it is it is almost silent and it is only $13.49 shipped.
Later...