z77 pro4

Hi guys! Im buyed the old AsRock Z77 Pro 4, witch cpu is the best for overclocking and price? i5 3570k or i5 2500k?

Hey I am making a build with a 144hz 1ms 24'' monitor (here is the build: http://ca.pcpartpicker.com/p/djzBJx). My budget is getting real tight and I would want to have 2 secondary monitors under 250$ total, they dont have to be for gaming, they can also have a 5ms respons time (up to 10ms max...