The 4200 mem rated speed is DDR533 mem which means it's rated to run at about 265fsb. And most of them need 3,4,4,8 or similar loose timings to do it. It should oc to the range of 280fsb. So with a 16 multi of the 3.2E you are considering, that is an OC for the proc of about 4.26~4.48. Those are tough speeds to obtain in a proc even with phase change cooling. IMHO, mem that will run around fsb 250 with tight timings is a better investment for a 3.2 or 3.0 proc. Most of the current crop of TCCD mem can do that with 2.5,3,3,6 timings. I just think that is a much better deal then 3,4,4,8 or 2.5,4,4,7 timings of the 4200s. The 4200 would be a good idea of you were buying a 2.4 proc and wanted to try to get to the 285~300 fsb range with your proc.
Just my humble opinion. It's all good.