coilovers shouldnt have a set drop height, they should have a range. Most are like 0-3" or 4 ". Coilovers are height adjustable and normal drop springs have a set height. Unless you go with the really expensive coilovers people have found the ride to be a little harsh. Some have had great success with Ground Control coilovers though. I went with springs because they were cheaper and I have no desire to change my ride height on the regular.

Toney
'97 RS 5 Speed (totaled)
15.4606@88.42 Mph
96 Toyota Celica GT
88 Toyota Supra NA-T (w/ sports package)
Got Boost?? Hell yeah I-6 turbo powah baby!