Get the 'CF' chip. It may be using the newer DSL Silicon as used on the AM2's. Which 'could' help with getting to higher frequency. At the very least it would run cooler and use less wattage. I am not 'positive' though. But it seems that all newer 'C' based chip codes, other than the 'CD' variant use the new silicon. The AM2's has similar 'C' codes.
Jason