Best GPU Overclock Tool

I dunno about all that app software that's being advertised in your link. But afterburner is what i use for overclocking my 560ti, does the job.

MSI AB is the shiznit indeed. I use its built in monitoring system to display my core clock/mem clock/gpu temp/ gpu usage %/ VRAM usage/ and FPS in games with the hit of a button, very very useful.