We still have standard bars in our R33 GTR, and run 3.2 neg camber with the shorter N1 upper arms (not adjustable), but the car still wants more camber, as the outside of the tyres still chop out.
The Dunlop D03 or Yoki A050 are the best tyres at the moment. I run my D03's at 30psi hot. The RE55 is old, and probably the least compeditive semi on the market (been discontinued in most places in the world).
Keep the rear soft of towed in, and run the rear ride hight 5-10mm higher than the rear.