Try 12/10 or 10/8 and see how you like it, spring are easy to change on coilovers and relatively cheap.
With my setup i find 10/10 to be good starting point but i can see the need in the future to upgrade the front spring rate to 12.
I have a very balance setup no understeer or oversteer.
When looking into my suspension setup it was extremmly hard to get any information on setup, and what parts to use and not use. I found that generally on sau people dont like big spring rate. Compare to what track car run in Japan and Europe.
I guess it depends what works for you and your setup.
Are you running stock swaybar? what is your allignment setup? (camber, castor, toe?)