What kinda setup are u looking for? What's your driving style and what's the road condition of the places u frequent to.
Through my humble experience if u are looking for a bit of performance & comfort side, u can't go wrong with Eibach springs. Want a bit harder, try Apex. Total performance, then go for coilovers. All good aftermarket springs should give a lowering of 2.5 cm from your original ride height. Any less then 2.5 cm is fine, but try not to exceed it as it will give your car a very unnatural handling while driving, unless u are driving it in a race track.
Hope this helps. ;)
Cheers