Just weld the rear diff. Lot of people use granada cosworth brakes as there the same cossie 4x4 ones and there cheap and easy to get hold of. I think you have to mod either the cailper or hub no matter what setup you go for though. As for the rear you'll probably be best off get a complete cossie 2wd rear beam and with that you'll get a rear anti-roll bar aswell.