One guy who is new with the porting and does good work with short turn-around that I can vouch for is slobanshee06. Although what locogato says is true, its not always the case. There are some new guys out there who are trying to get off the ground and don't have as much business as the guys who have been around for a while. But I agree, porting the heart and soul or your bike. Don't skimp on it.
I've had K&T cylinders, A&S Cylinders, Gorr Cylinders and seen FAST, wildcard racing and Herr Jugs cylinders. All do good work and I wouldn't hesitate to go to any of them for porting.
Good post loco.