12kg fron 10kg rear spring rates for dd
 

Is it gonna be a pretty hard ride for coils?

What spring rate offers a good balance of somewhat comfort and good trackability???

That's pretty stiff. Most coils for 240s don't come that stiff. It's usually like 9k/7k which would be a good balance of performance, comfort.

If you have to ask..... go 10/8 swift or 9/7 reg.

It is a bit hard, but harshness also depends a lot on spring and damper quality.

My current 9/7 fortune auto 500 setup is actually less harsh than any spring combination i tried with BC racing / K sport springs and bc-racing / megan coilovers, and i tried 4,5,6 and 7K springs.

Right now i wish i'd have gotten some 10/8 for the track.

12/10 seems a lot, unless you have aero ( like real aero, splitter and actually working BGW ). It wont be nice on the street either.