I would suggest some uprated anti roll bars like eibach etc, so you can have less body roll without having to go really stiff on the springs and dampers. At least you can have more comfort for the road, then wind up the damper stiffness on the track. The powerflex bushes did help my VR, less squirmy under braking on the front with the front bushes done, although i only did the inner rear bush. I have been told the innner front bush doesnt really wear out, but if you are tracking it i would do both.