Not sure which spring gives the lowest drop, but I have heard that the Eibach's barely drop the car at all. People seem to be happy with H&R Springs, or the whole H & R cup kit. Tein springs give you .8-1.8" drop depending on your model. For ultimate adjustablility, you can get Tein coilovers.
The pads are only for the rear springs. Depending on how wide your rear tires are, you might not want to drop the rear too much. If the rear tires are 265/35/19, the tires will probably rub, and you will need to roll the fenders. Also, there is more wheel gap in the front than the rear with the stock setup. I personally prefer to have the front look lower than the rear, to have the racey look.
If you use a thinner pad on the rears, your rear wheels will probably tuck, and the fronts will not. If you prefer the rear to tuck, then a thinner pad for the rear would be what you want.
__________________ 2004.0 C230 Sport Sedan
OEM Bi-Xenon 6000K. LED Taillights. Updated Foglights 6000K. Euro Clear Bumper Lights. W211 style Mirror LEDs. 05 C230 Springs. Stainless Exhaust Tip. 05 OEM Shift Knob & Sport Grille. 2 x 12" MTX Subs. 07 Chrome SmartKey. 20% 3M Tint. Hawk Ceramic Front Brakes. Akebono Ceramic Rear Brakes.
Can the H&R coils still be cut, if they are not low enough?I am running 235/35 and 265/30r19's.
Yes, you can cut any spring, but you will most likely get a very bouncy ride. It sounds like coilovers will probably be the best fit for you. Tein basic coilovers cost about $800.