Eibach springs and ? Shocks?????
First off, on lowering springs you're never going to get a caddy-like ride. As you drop the car, you have to increase the spring rate to prevent the car from bottoming out. Good shocks will help control the springs and in turn give you a more controlled ride, but it won't ever be luxury car smooth. As far as running into the 10s... I can't say that eibach lowering springs would be my first choice... 

