OE BMW tires are perfectly matched front to rear.
http://www.tirerack.com/tires/tires....fore%2010%2F10
If you stray from OE tires, you really need to look at the actual specs, revs per mile in particular.
For a staggered 22" setup, the only tire combo that should be used is 285/30/22 front, and 335/25/22 rear - though I doubt you can put a 335 tire on a 10.5" wheel.
If you're dead set on these wheels you may just look at running 285/30/22 on all four corners, which will give you a correct speedo reading and prevent any further drivetrain damage.