Correct me if I'm wrong but surely upragrading the front ARB is not a good idea on a car that understeers (as the standard mk4 does, well at least the FR does from my experience).
ARB's work by resisting the roll in the suspension and therefore increasing the load transfer of the wheels, resulting in decreased grip for that axle. So upgrading the ARB at the front will reduce grip there and increase understeer. That's why the rear ARB is such a good mod as it reduces the rear end grip so increases oversteer which cancels out some of the understeer, meaning that more speed can be taken into a corner without sliding straight off.
Strut braces are different as they stiffen up the chassis and reduce the flex in it which is better for handling.