Silent suspension ey? let me know how you get on with that.
I have experience of Koni FSD'S with Eibach springs, I also have experience with Bilstein B12 kit and Eibach springs with KYB excel G dampers.
Any future suspension work on any Alfa I have, I'll only consider something with the benefits of a system like KW V3 where I can change the height, rebound and damping. I think if youre spending good money getting things swapped, you may aswell get some good kit on which allows you plenty of options. I've learned all this in hindsight. Or I'll stick with original equipment if available. Saying that my FSD'S and Eibachs on the GT are really good, but if they break ill try V3's.