$80 to spend overclocking the 3570K? Pick up the Noctua. That processor will be great for playing LoL. The 3570K runs hot so there's a good chance you'll get close to 4.8 Ghz but I don't know if you'll reach 5 Ghz. For that processor, you can grab something cheap like the Hyper 212 Evo ($30) and overclock to 4.0-4.3 Ghz.