As you say, greens will be pretty much at their limit - greys with MSD's closed loop lambda would probably be a better bet.
Why don't you consider moving up from the standard cams while you're at it ? Perhaps leave the exhaust standard, but fit a BD12 or BD14 inlet ? (you could buy the cam instead of spending the money on the water injecyion kit, unless you've already got it).
What are you going to use the car for ?