Depends on the tracks you are going to drive on, fast straights with heavy braking for tight corners or flowing corners with light braking, ambient temperatures, track days in the rain etc
http://www.racebrakes.co.nz/ (has a bit about brake pad 101)
http://www.ebcbrakes.co.nz/ (there is a bmw race series 'street to full race spec' in NZ, ask them what has worked in NZ temps and tracks, brake disc/ brake pad combinations)
I would suggest 'yellow' all round, after the best disc machiner in you area has machined your discs, or if you doubt the competency of the brake machiner then new discs(if that is in the budget)
http://www.ebcbrakes.co.nz/ProductOv...8/Default.aspx