I7 - i5 which one to buy?

[thunderclash]

Hey guys, I'm planning to buy a new computer.

I'm in india, and not all models of graphic cards, CPUs etc. are available, but don't take that into consideration in your answer.

I am looking for a gaming build, with a HD 5850.

I was at first going with an i5 750 with a P55 motherboard, 600W Powersupply, No speacial cooling, 500 GB Seagate hard drive, a ATI Radeon HD 5850.

I'm going to play some graphic intensive games like - GTA IV, Crysis Warhead, Dirt 2(probably will get it free), and other casual games like Sims 3 maybe. Other than that I'll do a bit of multi tasking, like opening flash, Media player, and Internet explorer together. I may also do some 'lite' video editing and animation, but I'm no expert, just interested in the field.

I must stress on GTA IV, specially because I've heard that it is CPU intensive.. so, do you think hyperthreading will be a bonus? or will an i5 750 be just as good.

Also, will the P55 with the i5 be able to support 2 X 5850 in crossfire for the future?
In case of the i7, will 860 be better or 930.. for the buck..? Is it really worth it?

I'm a noob when it comes to pin point specifications, so I wont really understand technical terms.
Thanks.

 

[thunderclash]

Whats the performance difference b/w an OCd and one at clock speed? How much will the Turbo push the 750?

 

[thunderclash]

Best answer selected by thunderclash.