You dont need anything but springs But most people want to improve performance and get struts and shocks at the same time. If you just want a drop for appearances then you just need to have springs.
The one thing people dont really research is the type of spring and that is a big mistake. People throw alot of names around but what and how you want the car to ride is critical in the decision making. Do you want the ride to be like stock or do you want a firmer ride. some springs are to soft and others are to stiff and cause a really harsh ride. Some people buy racing springs and they were never designed to be on daliy drivers.
So not only drop but spring rate is equally important the higher the spring rate the more force it takes to move it. to low of a spring rate and a 1.5 - 2.0 drop and you wil be slapping the ground. here is a list of spring rates to chose from
SPRING FRONT REAR
1999 Cobra....................... 500 470
2000 Cobra "R"................. 800 750
2001 Cobra....................... 500 470
H&R, 99-01 cobra w/IRS
(except convertible)............700-760 685 (!)
H&R, 99-01 cobra
convertible, Super Sport......700-760 685 (!)
H&R, 99-01 cobra
convertible, Race..............750-850 770 (!)
Stock GT.......................... 400-500 165-265
Stock 94-95 Cobra........... 400 160
Stock 96-98 Cobra........... 400-505 165-265
Eibach ProKit cpe.1.5"...... 460-570 200-250
Eibach ProKit vert.1.5"...... 460-570 170-310
Eibach Sport...................... 660 260
Eibach Race...................... 700-850 200-260
FMS "B"........................... 425-530 200-300
FMS "C"........................... 650 200-230
FRPP "R".......................... 700-850 200-260
H&R Sport 1.5"................ 500-575 250-285
H&R Supersport 1.5"........ 700-760 275-300
H&R Race........................ 750 265
H&R Superrace................. 1020 300
Suspension Tech Street...... 725 230
Suspension Tech Comp..... 850 280
Steeda Sport 1.25"............ 650 200-250
Steeda Comp/St 1.25"....... 700-850 250
Steeda Full Comp 1.35"..... 850-1050 ???
Global West 1.0"............... 800 160
Global West Drag 1.0"....... 680 160
Global West Comp 1.0"..... 1000 160
Griggs coil-overs................ 350 to 500 +50.175 no TA
Griggs coil-overs................ 225 w TA + panhard
Dech Speeddrive 1.5"........ 1000-1200 210-280
Jamex 1.5"......................... 450-550 170-220
MAC................................ 600,680,700,800,925 160,170,190,215
Mac progressives............... 450-520 200-230
Saleen (Eibach ProKit?)..... 460-570 200-250
Kenny Brown 1.5"............. 650 ???
Roush (FRPP "R"?)........... ??? ???