AFAIK the BBK are not affected by the xi drive features, it is all about getting the BBK to fit a set of rims.
The massive kit that Dinan has will only fit a limited number of 18's. 17's will prob never fit. I've seen the kit, it is f'in huge.
Gotta go with 19" rims to fit the 355 mm BBK. A smaller kit like the Alcon or Stoptech would be a better fit for 18" rims on a 335.