Overclocked 3570K will smoke 3770 at stock speeds in any game, just saying. If you're getting a CPU and an aftermarket cooler, you should always overclock it no matter what, otherwise you're just wasting money and performance.
Also, you can't get a high enough overclock without unlocked CPU on the Z77 chipset as increasing the FSB even by a little causes instability because there are no features in place to limit the bus speed for SB.
Your best bet for gaming is 3570K with a decent cooler and a hefty overclock.