Hi
The z3 m coupe uses the same discs as the e36 m3 4 dr's. There are a few alternatives namely ebc gd series with yellow stuff pads or brembo. Look for a company called star brake and clutch in eastleigh in edenvale. Went to get my clutch from them. They will be able to provide you with some good advice depending on the application. I priced the ebc and it was about R4500 for the discs and the brembo was around the same price. I have the ebc's on my ///m and they work well.