with eibach pro kit springs you will improve handling and drop the car 1.25-1.5inches, with the sportlines you will see a little bit less fo an improvement in handling and teh car will drop 1.75-2inches.
if you mostly use teh car for cruising and aren't concerned with having the absolute greatest handling or perfect launch i woudl go for the sportline springs. the drop will look really sweet, still ride nice, and leave plenty of ground clearance for new jersey roads.
the other option is to spend a bunch of cash on coil overs. any ride height you want any time you want.
