For a full on track car i would run coilovers with 400lb fronts and 200lbs rear, the front set up will be pretty good if you can get the role bar back on there[drop links] think zoo do a kit for this anyway.

At the back is the biggest weakness on cossies i have been told. Best way to sort this without mega expensive GrpA set up is a Zoo GrpA style rear beam and an escort cossie anti role bar. Thats the route i am going to take but having all the kit is pointless if you don't get it set up properly.