Get some quality ram, and run SYNC in and AMD system. I can tell you from experience, that async memory timings KILL performance.
I'm running 230fsb, w/ mem async at 80% (184mhz), and performance is about the same as when I run 182fsb in sync. I'm only gaining about 30 points in 3DMark01 as a result of using 230fsb w/ slower RAM timings.
AFAIK, the Intel systems favor higher FSB's, even when running memory asyncronously. However the price difference between the RAM speeds are negligable, so get the best you can afford.