i don't race, but i've retired my mtb in favour of my 'cross bike, which is Shimagnolo. not exactly what you're looking for, but i like it - brifters and front derailer are Centaur, rear mech is XTR. gets pounded a lot, and works flawlessly.
cheap and easy to match the cassette, too - i'm running a 9-speed 105 right now...