are these any good for lowered cars?

 

they're more of a oe replacement than anything else. if you don't go too low, they should be fine.

 

whats really most important as far as ride quality goes? can a stiff spring with a good damper still ride nice?

 

Bilstein also makes a sport model and their PS99 coil over system.. not sure if it's made for your application but probably... the spring and shock are both integral parts of your suspension system so both are important...