Cosworth brakes on a Focus?! That's a new one on me.

Why not ST170 brakes? They're alot bigger.

As far as suspension goes either buy some really good coilovers or Eibach springs.

BTW If you haven't already invested lots of money in the 1.6 just sell it and buy one with a bigger engine when you're ready, it's much cheaper to buy and insure than a converted one.