Graphics Card: EVGA 012-P3-1570-AR GeForce GTX 570 (Fermi) 1280MB 320-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Note: Open to any suggestions on this one... not sure which graphics card will be the best bang for my buck.
You'll get a PSU that can handle CF 7970 (Mainly because the 7970's TDP is about the same as the 6970, only increased a little bit) The Motherboard can overclock pretty well, plus it has Gen3 so when you use an Ivy Bridge chip you'll have PCI 3.0 to use.
1) Personal preference, one good card allows for future SLI/CF
2) The i5 is plenty of power for even the best of gamers.
ETC: You don't need 16GB of ram, 8GB is good enough, even for photoshop, I'm currently doing large Photostitching (30000px+ pictures) with only 8GB of ram and it manages fine.
1)The only two card setup that competes at that price is 2x460GTX but I'd go for one card, less hassle less heat. Depending on the games you play, the 6970 will outperform the 570 and vice versa so check that out.
2)No, the 2500k (especially once OC'ed) can hold it self up against the i7 (2600k/2700k) in gaming performance no problem.
I)I would suggest getting an SSD, just overall better experience on your computer.
II)For the case I would recommend Antec 300 Illusion, very good build quality (strong materials, good air flow)
III)That is a lot of RAM, just saying, you only need 8GB tops for gaming.
IV)For your motherboard I would get one with NVIDIA NF200 as this one ASUS P8P67 WS REVOLUTION does.
V)Seriously include an SSD