My wheels arrived, delivered straight away by auto form to my work, great customer service. Went with a square set of 235/40/18 tires, decided to go with the Hankook Ventus R-S4 as I have heard many good things about it being a reasonably long lasting grippy semi slick, and managed to get them for $280 a corner through a sale on hyperdrive. Got them fitted and balanced and no scratches on the new wheels which I was very relieved about.
Got the m4 brakes mounted on the car with the seems legit garage adapters. Was a pretty straight forward install, just took some trimming of the heat/dust shields, especially on the rear. I ended up cutting a quarter of the front heatshields out to allow the brake ducting to be more effective on the front. The front brakes I used the factory brake ones, the rear brakes I used the m4 ones as they are slightly longer, to account for the much larger discs. As far as sensors go, I have left the original 135i wear sensors and zipped them out of the way, in fitter I may splice the m4 sensors into the 135i plugs. Gave the brakes a bleed with some fresh mogul rbf600.
So far it all works great, and looks fantastic with the new wheels, just needs a wheel alignment now.
Took the car out for some photos.