The 4690K is a good CPU, it's a nice match with the H75.
The H75 itself performs decent, not awesome but good enough when overclocking. There's a review on that unit here:http://www.guru3d.com/articles_pages/corsair_h75_review,11.html
The 4690K will overclock and run cooler than the 3770K@1.3V, so the cooler will perform better than with the i7.
A 240mm AIO will perform better of course, but it's up to you if the cost of that is acceptable just for the sake of overclocking.
Make sure that the CPU and motherboard are compatible and check if it's worth an upgrade in the first place.