depending on which type of springs you buy.
HR sport springs and UUC V2 springs use the factory shocks. They only lower the car just a tiny bit, about 1" max. Though I personally think this yields to all asthetics and almost no performance gain; for the price, its good for anyone who wants to lower the ride and have a tiny bit stiffer ride.
If you go for more radical spring sets like HR Race or Eibach race, they require aftermarket shocks. They usually lower a car from 1-2inches atleast.
To get good handling, you gotta get springs and shocks. Or you can go to the cup kit route, which includes matching springs/shocks.
Or you can go all out and get coilovers! which I like best