Depends on your budget you may want to go for the nickel coated AP Racing Pro 5000r or alcons
I went with pro 5000R and they feel amazing at high speed, but yeah they're a costly purchase...
Changing out oem M3 bushings (front monoballs and solid rear subframe) makes a huge difference! Look up the solid rear monoball bushing upgrade also it makes such a dramatic difference to the car the way it handles and puts the power down
https://www.e90post.com/forums/showthread.php?t=1640804