I was a owner of a Dell XPS 720 (not liquid cooled, still working) for 4 years, and now I decided to get a new gaming rig.
Approximate Purchase Date: In august (if all goes well at start of August, if not at the end) Budget Range: 4 000 - 5 000 CAD System Usage from Most to Least Important: Gaming, web... Parts Not Required: Keyboard, mouse, speakers Preferred Website(s) for Parts: ncix.com (canada) Country of Origin: Canada Parts Preferences: Intel and Nvidia Overclocking: Yes SLI: Yes Monitor Resolution: 1680x1050 and up
Biggest problem in the above rig is that the mobo is not compatible with the CPU you have selected.
The only way you could even get close to that performance in an LGA1366 chip is to get a i7 990X extreme edition and overclock it to like 4.2 to 4.5 GHz. ( 999 CAD )
Which obviously with your budget you can do if you choose to. But overall the i7 2600k is much better bang for buck.
You can't use that motherboard with that processor. X58 motherboards only work with the i7-9xx series cpus. Notice that the motherboard says LGA 1366 and the cpu says LGA 1155. These are the socket numbers, and they have to match.
Basically more memory would be better, but games don't really take advantage of them yet, since the available memory rarely exceeds 2GB on systems so the developers don't optimize for it. So as said above, in multitasking it will help. Go with 8GB and if you seem to be running out, which i doubt you will be get more