If you do any autox or road racing then you WILL need a coilover type system.

If you dont do any autox or road racing and are just looking for a more sporty feel and a lower drop then a shock/spring setup will do fine.

Coilover setups:
Ground Control with custom rates and Koni Yellows
Skunk2/koni
Tein, etc...

Spring/Shock:
Neuspeed, eibach, h&r, etc......