Your best bet is probably to get a complete set from a well known tuner like Koni, Eibach, Weitec, H&R etc. If you don't want to go low, get a complete -40mm or -60mm set, depending on your wishes. The lower you go, the more you need firmer shocks.

If budget isn't an issue, I'd go for a fully adjustable coilover set from Weitec or the like... that way you can set the height to exactly where you want it, and also adjust the firmness of the shocks... Fitment is also relatively simple, it replaces the whole shock/spring setup that's currently on your car.