I used the have the SiR cluster in my EG, it's a nice unit but to be honest it serves the same purpose as any oem cluster that is slightly off the motor's actualy readings. I have seen the GSR unit in, just like your ride, on many rides. It is nice. The best custom cluster set up was on "goldies" car, from the FF squad back in the day. He had a Si 99+ cluster and an EX mph reading on it, so the tach and fuel/water temps were amber and the mph was light light blue. It was a nice setup. All you have to do is wire everything up together.
Milan