Looking to order new components in the next 24hours, want to spend between 600$ and 800$ total (this is a little over.) If I was going to tune anything down, I'd drop the i7-870 for a i5-750 (for 200$ off of Newegg.)
The i5 750 has been Tom's best bang bang for your buck gaming processor for months and months. I would go with it.
I still think you only need 4GB of RAM. 8GB has got to be pretty cheap though and those cas 7 sticks look good. DDR3 prices just keep dropping.
You may want to look at the 1GB version of that card. The 768MB would be fine for resolutions under 1600x 900. Above that the 1GB version will serve you better.
Still not a fan of Sparkle but I have never owned one so who knows. But I have had 5 EVGA cards in a row with no problems. The Asus and MSI cards have got great reviews for having excellent cooling.
So I'll probably switch down the processor and perhaps the memory. If I degrade the memory, my gut tells me I'll get better performance out of 32bit windows than 64bit. I realize that some of the 4GB will we unreachable, but I figured the benefit of having memory addresses all half length would outweigh that. If I'm going to switch to 64bit, then I'd probably want to have the 8GB to take advantage of that.
I plan to run dual 1920x1080, so I'll poke around and see if I can't find as version with more memory. My current card has a 1GB, I don't know why I would have decreased it for a newer version. Granted, my current setup can pretty much manage 1920x1080 TF2 alongside 1080i video playback, so it can't be that underpowered.