?
At stock this chip runs at 10x200MHz (FSB)=2GHz. Even if you lower the multi and run at 8x400MHz (FSB 1600MHz quad pumped)=3.2GHz which is not uncommon you will only ever need PC6400 (800MHz) RAM to run 1:1 ratio. PC1066 is not really needed unless you are attempting 533 FSB+
On the other hand you may be able to lower the latencies on the 1066 if you are lucky
As i said with the E2180, run it at 10 x 333 for 3.3ghz with the RAM running at stock (PC5400).
Latencies make hardly any difference to C2D performance.