I'm using the Brembo Z04 sintered 4 pad kit on each of my 999R calipers (I have a 999 base model). Once they get some heat in them they work very well. But they are expensive. Make sure to get the Z04s for the 4 pad Brembo caliper, not the monoblock pad. Another pad kit suggested was the DP sintered. Both were recommended by the folks at BCM.
I just put in DP racing pads on my 749R. They feel a lot like the OEM pads (HH) that came in my bike. Which I think is a good thing, compared to the FF's that came in my 748 and M900. Nice bit, smooth and no fade.