Ive got the same boxes in my office, empty though, I think you will like the Bilstein set up, i have to say after two weeks it is a very refined set up, did you decide not to do the H&R roll bars? these have made the single biggest difference on body roll for me, but then again i think the Z3M already has 28mm and 19mm bars.
Did the parts from BMWpartsonline come through?