You need a 17inch wheel to fit over the front brakes. I have the euro 335i alloy donut in my 135i...
spare tire/wheel/notrad 36110445045 euros 120
jack/wagenheber kit 7110677536 euros 100
From what I understand BMW in the states can not order euro parts anymore. IF you really want a spare tire kit I would loo into the e60 tire/jack kit for $300.
Dackel