Full BMWPS with Koni sports (yellow) here. Perfect compromise between handling and ride comfort. I'd skip the FSD's; had those for 3 yrs; inconsistant damping.
If you decide go with aftermarket dampers instead of the whole PS kit, make sure you get the PS bumpstops with the PS springs. Dan@UnitedBMW will make sure you get the correct springs and bumpstops for your car.
2007 E90 335i, TiAg, 6AT, ZPP, ZSP, ZCW, 6FL, HD
Quaife lsd, ETS fmic, GIAC s/w, Dinan intake/exhaust/oc, KW/GC/M3/Meyle susp, Apex Arc 8, Mich PSS