that would depend on what rear sight you are going with. If you are sticking with the factory the notch is 0.140, which I think a 0.100 would be too narrow in. I like a 0.115 front for 0.140 rears. If you are going to use the dawson rear, their notch is significantly narrower so the 0.100 may be ok but most seem to prefer the 0.090.
the height will be determined by the rear sight as well as your load.
I will be going with a Dawson rear sight, and prefer the narrowest blade I can get. I don't want the rear sight cranked way in the air, so I would image the taller front sight will be best...
I have a .100" Dawson FO front sight on mine and it was fine with the factory rear and the Warren Tactical I have on it now.
If nobody around there has one, I can loan you my M&P sight pusher (MGW). Unfortunately, it won't do the front on the Pro/9L and I had to cut the last one out it was so tight! R,
Thanks Chris, but I think I will just send the sights in with the gun when I have the trigger and stippling done.