you might need sway bar end links for either front or rear. you might find them to be quite worn or maybe even broken. 2 bmw's suspension work i did, both had the front right end link broken at the ball joint.
i also recommend the reinforcement plate for the rear shock mount. it's not totally needed since your new setup is stock and not overly stiff. but it's cheap and never a bad idea. search "z3 rsm reinforcement plate"
other than that you should be good.