If you were/are on the X79 platform which is the only chipset that supports quad channel, yes, you should be using four sticks. If you are on Z97/Z87, etc, they are only dual channel. The 4930K is X79 so four sticks is what you are looking for.
As far as memory goes, both memory speed and the timings matter in over performance. The big difference is if you actually can notice said tweaks and improvements outside of benchmarks... in a lot of cases, not usually. In regards to the timings, the lower the better, and speeds, the higher the better. The article ends essentially by saying pic something between 1600 and 2133Mhz with the lowest timings you want to afford... (note the build I picked 2133 with your budget).