I think the Koni Sports would help you. A different set of springs would too.
I also didn't want to lower my car that's why I went with 2011 M Sport springs instead of aftermarket springs. Beginning with the 2011 model year BMW switched from progressive to linear springs. I picked up mine from somone on the forum who switched to aftermarket springs.
2009 BMW LeMans Blue 135i/Dinan Stage 2 tune/Alufelgen SF-71s/M3 suspension components/Koni Sport adjustable dampers/ETS FMIC/M3 paddle shifters/Alpina B3 TCU flash