Roadfly brackets, Porsche calipers, M3 (non-CSL) rotors. Total cost should be lower, calipers are better and lighter (fewer pistons though if that matters) and everything is off the shelf replaceable. And everything tucks nicely under 17" wheels for those of us that aren't baller enough to have a bigger winter setup. The only downside is that Porsche pads dust like a mofo, much worse than stock BMW pads. I suggest getting different pads from day one.
The BMW one do look pretty though.