Cooling Questions about the Aquagate Mini

My friend (and possibly me as well) wants to buy a Cooler Master Aquagate Mini 120mm version from eBay and has some questions. He has a EVGA 680i SLi and I was looking at the size of the waterblock and it may be too big to fit on the board, as there are MOSFET heatsinks on one side and the NB cooler on the other, both only about 1cm from the cooler. Also, without a CPU fan will those power regulators overheat without that airflow over them?

Also what kind of overclock could he expect out of his E6600 and will it be substancially more than his current Golden Orb II offer him? Would he be better off getting a Zalman CNPS9700 or 9500?

Thanks for answering.