ultimate slayer - I have a similar setup to what you want except i just went with 1 4870x2 card and i did go with 8gb of ram. The rest is the same. I even have the stacker 830 except i went black.
I decided to do air cooling and here is my configuration:
2 Fans in the front - Blowing in
2 Fans on the side (custom windowed side with only 2 fans instead of 4) Blowing in
2 Fans underneath - Blowing air in
1 Fan on top - Blowing out
1 Fan in the back Blowing out
2 Fans in the PSU
1 Fan in the CPU Heat Sink
1 Fan on the Video card - which i modified to have it run at 90%
Noise doesnt bother me so i bought 8 fans:
2 Delta Fans that blow 200+CFM
6 Scythe 3000 RPM 150+ CFM
Seriously the air flow is so strong it is no wonder that no parts have blown off yet in my case. You def want to tie any wires down. Anyways i just wanted to state that i have similar setup and you can buy some powerful fans that keep air flowing through your case like a tornado and im OC'd at 3.6 with no issues.
Good Luck.
PS Did i mention that it is worse than being in a server room or server farm when sitting right next to it?