[Wasp_Factory]

I believe your wheels will be 8J front and 8.5J rear.

Your best bet would be to go with 245/35/19 front and 255/35/19 rear. This stays within the 1% delta for xDrive and replicates the ZTK tyre sizes. 245 is the max tyre width you can put on an 8J wheel and these sizes are available in MPS4S.

Your scrub radius will already be outside of spec with the spacers, but at least you are keeping it reasonably close to BMW set up.

I run aftermarket fully forged 8.5J front, 9.5J rear with MPS4S* at 245/35/19 and 255/35/19. I can promise that grip and traction are more than adequate for fast road driving.

One last point - it is worth looking for the BMW star (*) MPS4S as the compound is slightly different to standard MPS4S. I also believe the rolling radius is very slightly different as well if you look deeply into the specs. There is a good comparative tyre test online somewhere.