I'd take a 5820k though for the multitasking and to future proof on cores but if all you do is game then it might not be necessary. I personally own these three in my gaming rig and can attest that they will still be overkill in the next- nextgen of gaming. The cooler is awesome, it cools my CPU under stress at 4GHz staying under 71C which is amazing for a sub-$100 dual rad AIO. Both CPU's perform so well anyway but more cores always win when doing more. In ssimilar situations the 6700k keeps up fine with the 5820k and even surpasses it in some instances where more cores doesn't equal more performance. Since games are not optimized at all these days, I would say more cores will give better performance when push comes to shove with all the AAA games coming out broken at launch. Plus Arma will utilize all 6 cores and 8 cores on the 5820k, 5930k and 5960X
https://pcpartpicker.com/list/Kkzv8d
CPU: Intel Core i7-5820K 3.3GHz 6-Core Processor
$368.99 $368.99 SuperBiiz
Cooler Master MasterLiquid Pro 240 66.7 CFM Liquid CPU Cooler
$96.75 $96.75 Amazon
ASRock X99 Extreme4 ATX LGA2011-3 Motherboard
$159.99 -$30.00 $0.99 $130.98 Newegg
Base Total: $625.73
Mail-in Rebates: -$30.00
Shipping: $0.99
Total: $596.72