That is the MAXIMUM speed of memory your motherboard will support, but it really has no bearing on what type of memory you should you buy. It just means that it can support memory up to that speed. But if your processor does not need memory that fast, it is kind of a waste to spend money on it, right?
For your processor, DDR3-1333 with good tight timings is what you need. You can buy DDR3-1600 to give you some overclock headroom if you plan to overclock the processor.