Just looked at some pricing - holy sht. The exchange rate really crapped on local hardware prices.
The balancing looks about right now (assuming 7970 & 4670). I wouldn't worry about the CPU...focus on HDD/SSD/GPU.
Do not go higher than 8gb. You'll not see an immediate benefit from 16gb and the prices right now are not all that great. 8gb now another 8gb later...thats why I wanted you to buy a 8gb stick not 2x4gb...makes future upgrades easier w/ slots.
HDD...def at least 2TB. You can buy 4TB right now, so even a 2TB is well behind the curve. 2/3TB is the sweet spot right now. Esquire sometimes runs nice specials on hdds.
NB my GS600 recommendation was made before I knew you wanted a possible xfire. I don't have the necessary experience to judge xfire setups tbh. However, I'm inclined to think it'll still be fine though. As I said I've got an actual Watt meter & I've never seen it go above 255Watt. (3570k/7950) with GPU load/idle (Bitcoins) resulting in a 150W delta. I *think* it'll be fine but can't say for sure.
SSD...focus on space rather than speed. I've got a 128 and its pretty thin. Now I know you said you've got one for work but its a whole new ball game once you start loading steam libraries onto it. 256 is stupidly expensive but I'd really try to push for 256 - even if it requires sacrifices elsewhere. If you go for 128 then you'll need this (see SP/MP split above)
http://schinagl.priv.at/nt/hardlinkshellext/hardlinkshellext.html (yes link looks dodge, but IMO its OK).
That mobo you've got there...I don't feel qualified to tell you what to buy, but I can tell you that the one you've got there is definitely wrong. You need double x16 PCIe for xfire setup, not x16 + x1.
>Case, something with good air flow
Still battling with that one myself. From what I've learned though: Pay attention to to GFX length...cases have specific max lengths. Big fans better, but has to be mobo driven else the speed control is nonexistent. Most mobos limited to 2-3 case fans max. Watch fan placement for xfire.
>Also wouldn't getting a crazy awesome GPU mean that the CPU would be holding it back?
No I wouldnt worry about that. Modern Intel CPUs are beasts & all the processing is moving to GPUs anyway (see CUDA etc).
>GPU, something beast
Beast def, but don't buy top of the range - pricing premium will kill you. Lagging behind top of the range a bit is where its at.
>CPU Cooler, closed water loop would be nice
Unless your a hardcore overclocker I'd suggest running with stock fans - just temporarily. After like 1 month you'll be in a much better position to identify which components are running hot. e.g. In my case I found that I got lucky on GPU ASIC draws & CPU too, so I can undervoltage both something wild - thus fixing heat issues without any fancy cooling or sacrificing performance. Point is - wait & see.