although the KW V3 are extremely good dampers they come with very low spring rates (11/8 kg I believe) and as the fronts are conical springs extremely hard to get alternatives, my assumption that they are so low would be that they are not specific to the ISF bat cater for the full IS family, if you are looking to retain stock ride height the spring rates are not ideal, although not the end of the world you will loose a but of that dynamic feel,
If you are however planning to to reduce the ride height remember this will change the roll centres and will need to be stiffer sprung, a minimal drop you in my opinion need a 14/10 setup, bigger drops a 16/12 setup (I run a 16/12 setup)
If you do go down the coilover route, whichever brand you go for make sure you have them professionally setup on corner weights as they generally come with only enough preload to stop the spring coming loose during shipping, the whole point of being able to adjust the preload and to a certain extent the height is that you can match the weight on each corner as close as possible, when you see people slating coilovers of any brand this is generally because they have not had them setup correctly.