I refreshed my suspension last year. Best mod I've done to my car thus far. I went with an H&R touring cup kit. Lowers the car just enough so it doesn't look stock, isn't too stiff (progressive springs) and wont kill your back when daily driving.
I refreshed my control arms and bushings. Went with Z4M RTAB's along with Vorshlag RTAB limiters. Car is extremely tight and handles great. The only thing I would do to it is maybe sway bars and better tires. (I run Michelin Pilot Sport A/S+'s)
Touring cup kit claims a lowering of 1.25" front and .75" in the rear. It seems slightly more for me. I drive in DC where roads are Armageddon and it handles fine. I wouldn't go any lower where I live or I would need a new front bumper every 3 months.