| A very slippery slope, this. Also, do a search as this has come up before.
The front spindle is different as are the fork bottoms. You'll need new forks. You'll need a new rear swinging arm with the corsa hub, which is much larger then the road stuff.
You probably won't like it, but my advice is don't try what you're about to do unless you get all the right bits, which is mega expensive. Spacing the discs or getting a sprocket machined will be the least of your worries. I know, I've got an RS. | 
Threaded Mode