Leave swaybars stock. Softer springs. Make sure whats there has good bushes and works appropriately. Not too much caster, maybe 3.4 degrees. Also, perhaps about 2.5-3 degrees negative camber, and you will still scrub the outer edge of the tyre if you drive it hard enough. Zero toe if your steering rack is perfect, otherwise if it has some play, toe it in a tiny bit. I find height is critical, as in the right ride height front to rear. It changes the handling a lot. Lower the rear too much and it will create understeer, raise it too much and you can create oversteer issues. Pinion angle can be tuned, and there is a sweet spot for good grip. I find it better for the cars balance to have an equal sized wheel and tyre on a car with as little power as a 4age ae86. It makes it a lot more predictable. With 8/9 combo and appropriate tyres you may find it hard to make the front steer right, it could tend to push the front through corners with more rear grip than front.