comfort is relative
but you should read any of the billions of other coilover threads for people that want to make their sports car comfortable AND handle like an F1 car
bottom line:
good valving can make even stiff springs "relatively" comfortable, i.e. no bouncing uncontrollably
at this point, though, you're complaining about eibach springs being too harsh
so i would recommend you buy a lexus and leave it stock
you bought an automatic sports car, slapped on lowering springs, and now you're complaining about the ride harshness
you really need a different car
try this