Nice.
I've recently purchased some of the
G.SKILL CL5-5-5-15 PC-6400 2GBx2 kit sticks 1.8-1.9V
from Newegg @ $170 for my last Q6600 system, they seem like the
best deal for 4GB of matched PC2-6400 sticks to me.
http://www.newegg.com/Product/...x?Item=N82E16820231122
Though there are also the PC2-8000 G.SKILL 5-5-5-15 2GBx2 sticks for $190.
http://www.newegg.com/Product/...x?Item=N82E16820231145
These need 2.1-2.2V and at 500 MHz they're not a TON faster than the
previously mentioned 400 MHz sticks, so the extra cost is only really justified
if you need to run faster than the 440 or 450MHz that the slower sticks will
usually easily do.
There are some great deals on even slower memories there too for 2GBx2 kits,
though I'd certainly go with PC2-6400 or PC2-8000 for overclocking the X32x0
since it has a lower multiplier and so you'll need the higher FSB and memory speed
to get the CPU over 450x8 or whatever.