Usually best to go with fewer number of larger sticks, 2X8 in your case. It is just easier from a compatability standpoint, and on a 2 channel memory controller, 2 sticks is all you need.
EDIT: Don't get hung up on timing. The difference between 9-9-9 and 10-10-10 isn't something you notice outside of benchmarks. More important is the speed (1600/1866/2133), and even that is not the big factor it once was. 1600 is the price/performance "happy" point.
Voltage. Try to find memory that runs it's advertised speed at 1.5v or lower. Less voltage=less heat=less memory controller stress.
Edited by dpunisher, 09 January 2013 - 05:41 AM.
I am a retired Ford tech. Next to Fords, any computer is a piece of cake. (The cake, its not a lie)
3770K @4.5, Corsair H100, GTX780, 16gig Samsung, Obsidian 700 (yes there is a 700)