Thanks to GRAthos, I know a good place in Dubai where I can get a computer built in under 2 hours. Due to various circumstances, the best specs they can offer me are as follows. (Bear in mind that I just want to run CoD at a consistent 30FPS over london at almost max settings, and I can always upgrade parts in the future):

GTX 580 1.5GB

i7 2600k at 3.3ghz

8GB of RAM (Kingston)

850w Power Supply

Nice Case

These are my final specs, are they good enough to run at 30FPS over London?

And thanks one more time to GRAthos! Your advice was much appreciated!