I'm in the middle of doing this 05 wheel swap. My plan for the front wheel is to use the busa axle and make two .08" spacers (one for each side of the wheel) by cutting the gsxr 1000 axle spacer off the old axle. Then shiming the front calipers .05" using washers. For the back i'm going to mill down the brake hanger .125" on the side that faces the swing arm, while using the gsxr 1000 rear spacers.
I have no idea if the is the correct way of doing this, but i'm going to give it a shot....