if you wanted....i dont have one myself. its fast enough. Cooler wise yeah the stock one isn't great its fine for if you never overclock. Even Tim i think if i recall his system stats, has an i5 2500k
I went for something silly 8]
A nice 33C on idle and 60C at load @ 4.7 tho and on super slient mode

, The stock does something near to that on stock settings so dont worry if you won't want too, but to be fair even at stock it was fast.
here are some more reviews which always help my mind.
http://www.techradar.com/reviews/pc-mac/pc-components/processors/intel-core-i5-2500k-917570/review
http://www.techradar.com/reviews/pc...phics-cards/amd-radeon-hd-7950-1058628/review
http://www.techradar.com/reviews/pc-mac/pc-components/motherboards/asus-p8z68-v-lx-1072516/review
The only bones i have about the setup i gave you is that if you wanted to go crossfire or SLI, you'll need a better mobo that supports 16x on both pci lanes or 8x at least (i think i recall reading its really hard for a single gpu hard to use the full 16x but dont hold me to that). this is what i went for, buts avast for more.
http://www.ebuyer.com/338468-asus-m...55-hdmi-supremefx-x-fi-maximus-iv-gene-z-gen3
which has dual 8x ports but im silly and ive still only have one gpu...for now...see i'd want to get three screens and see if i needed another card instead of getting two and not needing the extra power, anyhow
and at least 850w psu for both cards at least otherwise they be unstable and the psu would be stressed. (you really only want a psu running at 85% and not 100% all the time)
I would also like to lastly add that even if you have that super system, Rfactor 2 still (in places) runs pretty bad, some examples would be on the grid at a start of a race. this also depends on your settings i think i have mine on high to full with AA x4 at 1920 x 1080, HDR. But its still very much un finished and i noticed a masively improvement from an phemon x2 555 BE which had only two cores.
its still needs work but it will be great. look at project cars which purs on my system (along with all the big tiles bf3, skyrim etc etc) its a shame project cars feels likes rubbish! also i reckon running 3 screens would be taxing to say the least, this is why i think isi might of picked this route for 3 screen support to which you wouldn't need all the candy!
makes you think!!!