I agree the 5-leaf rears are too hard for real-world road use, but I'd be wary of talking to racers for advice on suspension setup, as our roads and driving conditions are simply nothing like any racetrack.
I have the latest 4-leaf springs, panhard rod, anti-tramp bars, & AVO adjustable shocks on the rear, and the Suplex kit on the front. On the potholed and crumbling roads of Gloucestershire I think it works very well indeed within the limitations of a live axle design.
