I would get a 6970 over the 570 for having 2GB over 1.3, more future proof. I know it's mostly Nvidia fanboys here though so I'm sure you will refuse to buy any AMD card. But that's what I would do, 570 already does not have enough VRAM let alone going forward. Look at me for a good case in point, when I bought my 4890 in 2009, many advised me 512MB was more than plenty. I stuck to my guns and got the 1GB version, making it a MUCH more viable card today.
I would also DEFINITELY get 16GB RAM in any build I built today. The stuff is cheap as water, but you can be sure if you go to upgrade your RAM in a few years, it will be quite expensive, so buy all you'll ever need now, at the time of your initial build when it's cheap.
I learned this the hard way, bought 4GB of DDR2 in my 2008 build, now I really wish I had got 8GB. But at this point since I did 4X1GB sticks, I would have to basically throw out my old RAM and purchase 8GB of new DDR2 in 4x2GB format, which now goes for about $80. Not worth it, would be better off putting $80 toward a new build.
The point is there will come a time in 2-3 years when 8GB will seem a little light, but by that time DDR3 will be a lot more expensive.
Edit: Speaking to fna84's build.
Honestly it's a weird time to build/upgrade. The next time I really think a big jump in PC specs will be needed is when the new consoles hit in 2-3 years. Until then your power will be idling. Accordingly, personally I may try to string along my aged Q6600 build even longer.