If you move the front fan connectors up a bit, you can still use the push-pull configuration. Otherwise you need to remove the cooling fins from the first memory stick, but I prefer the first approach.
The NC-C14 overhangs a bit to the side, but you have the choice to install it such that the overhang is to the right or left or below the CPU. Just don't install it such that the heat pipes are at the top. I've put the NH-C14 in my build (ASUS p8p67 Pro, i7 2600K, 16GB GSkill Ripaws). The clearance was tight but there was still room to spare with both fans installed.
It seems I need only one fan anyway. I finally got to test my setup yesterday and installed a chess program that runs my processor at 100%. I run it at 100% for 10-15 minutes and it was at 61C at maximum. Idle it is 36C. I am pleased with that.
The cpu fan stays at about 1200 RPM all the time, but when it gets hot the cabinett fans increases from 1100 to 14-1500 rpm.