I run 245/40R17 or 245/35R17 Toyo R888 or Toyo R1R on my wagon. They are fitted on some 17x9 +45 Rays wheels. I'm currently on 8kg/6kg spring rates and I have a bit more droop than the pictures, but not lots more. I like the way the car turns, feels confident, and easy to control for me. I don't know if the ultimate grip is there, but it feels ok so far.
How stiff do I need? Am I too stiff already? I have a Cusco adjustable rear bar on full stiffness.
Long travel plus stiff springs means higher ride height right? I have to admit that appearance is important to me since the car is also a DD.
I am on JIC FLT-A2 now and although people always complain about their ride quality, I think they are decent on the track. Yes, they are a bit bumpy just driving around.