if you fit drilled/grooved discs and greenstuff pads you dont need to change your calipers or anything else if you buy the correct parts for your model.
drilled and grooved discs do not make a real difference to the way the brakes dissipate heat, and it is the heat build up that is causing your brake fade.
to improve the situation you need to fit vented discs, they lose heat far better, and since there is more metal they can soak more heat up before brake fade occurs.
my 1.6 had solid discs, and the brake fade was very noticable and occured fairly quickly. compared to my 1.8 with vented discs there is a big difference, especially when you give the car some abuse for a long period in the summer on B roads (as we all do from time to time
). plus the 1.8 brakes work better as well so you're winning both ways.
fitting the brakes from a 1.8 would be easy. you need the discs and calipers and pads, but everything else will not need changing. it will make more difference than drilled/grooved discs and greenstuff pads, and it will be cheaper.
