ASRock M8 Z97

Hi, just bought the ASRock M8 Z97vand saw your great review!

I'm wondering if you can help with a little advice.
I'm using an i5 4690k and the stock cooler, however I would really like to get the absolute best cooling I can on this board.

I don't want to have to remove everything including the mother board, so my question is:

Does any know what the best cpu cooler is that I can use in this case, that uses the STANDARD INTEL PUSH CLIP type fit (so not a back plate fit.

I'd like to remove the standard Intel cooler, then just push into the existing fit, a new better cooler.

Could anyone give me any advice on the best low profile (or small enough to fit) cpu cooler is that I can use in this case, that doesn't require a back plate.

Hope you can help.
Thanks in advace