If you are keeping the 1.7 standard, then a set of ST150 front calipers and discs will be a good upgrade. They will fit under 15" wheels too. A better set up is either ST170 calipers and ST170 front discs, or Mondeo Mk3 calipers and ST170 discs, but youll struggle to fit them under anything less then 16" wheels. They are both easy to get hold of parts, there are loads of other options available, Escos front discs and calipers are also a really good set up.

All these bolt straight to the hub, you just have to re-drill the holes in the hubs, i think from 12mm to 14mm. Either way, they just need opening up a little.