You don't have to renew the pipes, if you want to retain the rear load valves then you can simply remove the ABS modulators and get some copper pipes to patch up in-between the steel ones. (and then u also can retain your master cylinder)

If you want to get shot of the rear valves and have fixed rate ones in the engine bay then new pipes may be easier. If you decide to change the master cylinder make sure it is the same/bigger size as yours!!!!!!