one of the reviews of that heatsink said that it has a 65W max thermal dissiapation. The 6000+ could need to dissipate up to 125W. I use a huge gigantic scythe and my temps stay below 40C under total system load.
i agree, these cpus run hot naturally, yet ironically temps around 60c on a continuous basis arn't recommended. look for something that directs heat roughly an inch or more above the cpu with a decent sized fan attached to it.
price doesn't necessarily determine quality when it comes to hsf (to some extent) id recommend using google to find reviews of AM2 compatible hsf's and find the best one that's within your budget.