You have drums on the rear of the 1.6 so you'll be needing to fit a couple WRX set up at the back to get rid of the drums the fronts while bolt right on if memory serves me right.
look at imprezasport.net , im sure some one on there has done what your thinking of doin , My old 2.0 r hawk was a straight swap for classic 4 pots so id say you should be ok ,