Not sure about the FSD's and as Damo points out there was some talk about not fitting lowering kits to the Koni FSD's.
As for the Eibachs go for it, these are fitted to my standard shocks.
I've also got a brace of braces (


) from GTT and would say the 20-30mm Eibach kit really works well with the stiffer chassis.
Have you thought about the GTT boot brace too?