The pc will primarily be used as a gaming machine, but I also do some video editing for work as well (I have a NAS for the video editing stuff, SSD just for OS). The reason I wanted to get the 12 gig ram kit right of the start is last time I bought 4 gigs and when I was ready to upgrade to 8 I wasn't able to find the exact same ram as I was using. I wanted everything to be matched perfectly.
My PSU is good, but right now I'll be going single card. When i get my second 470 I'll upgrade the PSU at the same time.
I think I may get the EVGA Superclocked edition of the 470. Reading reviews and benchmarks it seems to run cooler, I'm not overly concerned about the 0.25 FPS increase from the superclocked but seems like better cooling maybe?