I'm using one of Johns Precision Turbochargers SS2 profile; recommended by Craig over 3 years ago.
I cannot speak highly enough of John, and the quality of his workmanship. He invited me to his workshop, and was more than happy to explain the theory behind what he builds, and it performed exactly as he said it would.
The guy does excellent work, and shared my excitement when the car pulled a good time at the drags.
This was in stark contrast to the other turbo builders who just wanted me to stop asking questions and start throwing money at them.