to be perfectly honest, I don't see a real difference between 1333mhz and 1600mhz. So go with the 1333. And the brand shouldn't matter, but look at the manufacturer of your motherboard's website for a list of compatible ram. This isn't 100% necessary but making sure that the ram you buy is on that list will save you some trouble... If its not on that list it probably will still work but thats not a guarantee.