another thought about your question...
ground control and skunk2 do have "coilover kit" , but you must know these are not the "true" coilovers, they are more the springs, then the complete set of the coilovers. and so their price is much less.
Skunk2 Coilover Kit is selling for $363.00 on clubrsx.com
and i'd imagine ground control is cheaper.
i wouldn't suggest buying these kinda things, if u wanna lower the car, just get the springs. Eibach sports line $244
drop more than 2 inch i think, and Eibach pro kit $244 which is what i have, drop about 1.5 inch. Eibach has pretty good products. or you can try Progress springs $164, Skunk2 $181.
price obtained from clubrsx, usually they have the lowest price around.