Yup,turbo. I have heard that the box will eventually kick the bucket, i do have a RB25DET box on my list of things to do.
As for where the click is, im not sure exactly where it is, i just know that it happens when i select a gear, i would assume it was a pivot point, it would happen every time i pressed the clutch.
(i know very little about cars, hence why i bought this, to learn on with friends)