1.
http://www.overclockers.co.uk/ is a good site and good deals but there might be better offers elsewhere.
2. I7 2600K or I5 2500K both good cpus.
3. Not sure i always buy Intel so a bit biased
http://www.overclockers.co.uk/produc...=43&catid=2053 check these bundles out.
4. Clod uses a lot of Vram so personally I would go for the 2GB or if you can afford it the 580 3GB version, I own a ATI but get the impresion that nivdia will run this game better than ATI like it was in 1946.
Hope that helps.