is the NF7-S picky about memory?

I'm finally getting one of these boards to replace my VIA266 board. I have a stick of micron and 2 sticks or samsung memory. I'm wondering if you guys think mixing my memory will cause problems w/ the NF7-S.

I guess I'll through this in. Will copper heat spreaders help my overclock of these "cheaper" sticks of RAM. I know they can hit 166mhz but w/ my current mobo I haven't been able to go over that.

Thanks for any thoughts.