Do you plan to put the car on track at all? That will narrow the choices on springs because you could eliminate linear springs since they will give a rougher ride. Unless you want to slam-it, in which case you will want coilovers.
Im on sportlines. I have no complaints other than that my handling wasn't THAT improved. But still better over stock and a full 2 inch drop in the front and 1.9 in the back. Im also on Koni Yellows and those are shorter struts than factory. So im a little lower than most on sportlines.
I am not sure on that one. With a 2 inch drop you might.
You may also want to think about upgrading your sway bars, at the very least the rear one. They are the best mod for handling, since they control body roll.