The top front brace that goes across the engine is just for show on a Golf MK2, it won't do jot for the handling or anything else. You will probably have to relocate the expansion tank to fit it though.
The front bottom brace is a very good thing on the MK2's, and will make a difference if you fit one, just make sure you torque it up right, there's a lot riding down there!
I think also the rear brace does work, though probably not as much as the front bottom as the car's FWD.
Be carefull of making the car to rigid though....