I've built 3 systems so far with MSI P6N SLI platinum boards and I couldn't be happier with the results so far.
My dad's system was the first that had an E6400. Didn't use the north bridge cooling fan and used the stock intel HSF on teh CPU with some AS5.
I overclocked that about 400mhz from stock and it purred like a kitten for 28 hours through the torture tests.
I just finished on my dad's brothers PC using another P6N plat. and an E4300 Allendale C2D that I also used the factory intel HSF and is running at 2.4 ghz.
My own personal system is in my sig.
Overall, I couldn't be happier with the boards. They all showed great flexablitiy, stability and the bios is easy to work with. Best of all is their price.
As for ram, Patriot has a $50 rebate right now I think on their 2X1 gig DDR2 1066 ram. I'd jump on that. It's workign really well in my system.
Otherwise get some of the geil or ballistix or XMS2 DDR2 800.