There's a good chance they'll work together. It partly depends on how you arrange the memory in the slots. I think the right way is to put one set of memory in channel A and the other set in channel B.
As to the memory speed, that depends on your motherboard. Some will automatically pick up the 1600 MHz speed, others will require you to enter that speed manually in the BIOS.
The overclocking forum here on Tom's is a good place to start learning.