I think he is referring to the lower control arm. Ball joints may be different depending on the year of your car& what you are swapping to. Best bet is to use the lower control arms that go with the new struts. Steering arms, as far as I can tell (quick measure notwhile assembled) are the same for the 1200 & 120y. Get the sway bar as well as 120y is thicker than 1200 (20 vs 17mm). Strut tops should be a straight swap over- you want to retain your original ones- but you will obviously need spring compressors to do it. You may not need to change your master cylinder if you have the dual resivoir type- just take the plastic check valve out- search for discussion on this.

Edit:Moving a bit fast for me.... thanks cable tie.