Athlon Am I Am Building My Own PC And Already Have 2GB Of 667 RAM. Is The AMD Athlon 64 X2 4800+ Brisbane A Good Match?

I am building my own PC and already have 2GB of 667 RAM. Is the AMD Athlon 64 X2 4800+ Brisbane a good match? - athlon am

I know there was a correlation between the FSB and RAM speed, but apparently no longer valid for the new line of AMD chips. So not really fit what the processor speed of 667MHz RAM I buy?

On a side note, the 5600 + Windsor and really worth the extra $ 50 in 4800 + Brisbane? So you have some opinions. Thank you!