i could tell you my spring rates, but it might feel different depending on what schocks your running
You must remember that although the springs make up the actual AMOUNT of movement and suspension travel per given force, shocks control the SPEED of that motion.
For example, a very stiff compression shock, combined with a very soft 2.8 kg/mm OEM front spring, can feel VERY harsh...and at the same time, an 8.0 kg/mm spring coupled with a decently soft compression (high rebound) shock can feel supple and comfortable...
It's all a balance.
Japanese performance shocks in general have high compression valving and makes any spring feel hard. Tokico and KYB both generally fall into this category. KONI and many European sourced shocks will have softer compression valve with a high rebound valving in general. The former allows high speed stability and supple ride qualities while the latter is suited to making fast, stable attitude changes. Most people will find that former is easier to stay consistent, while latter is sometimes preferred by advanced drivers who can control a more pronounced attitude change of the car.
Great suspension though is never made by general assumption and it can vary by a million different factors and driver tastes. And the best way to figure this out is to compete if you want to be fast, and becoming ultra-sensitive to inputs and feedback, if you want to be a testing engineer. A little of both with experience and help along the way will make you a good set right for your needs.