I am looking for an ac connector just like this (well, a round pin and the other two as show, as you would see on a normal pc case/power supply), but with a round mounting hole.

 

This is an IEC connector.

http://uk.farnell.com/multicomp/jr-101/inlet-iec/dp/9521631?Ntt=9521631

I have never seen one that fits into a round hole. They are normally screw fixing like you show or "push-fit". But need a rectangular hole.