You can sand the lines smooth in the valleys of the finger grooves, even on the Pearce extensions. With an inner tube stretched tight on it, the grip is'nt noticably larger even without messing with the sandpaper or file.
You may find the 10mm Glocks are just too large for you to feel comfortable with. You would'nt be the first and your G33 is'nt a bad 2nd. choice. A 32 will get you another 3 rds. and 50 FPS over the 33 in a pistol very close in size to the 29 but smaller grip and lighter. Good luck.