Question - why do you want the coil-overs ? What are you hoping to get from using them ? The wording looks abusive, but it's just questions to ask yourself.
Steering arms (or knuckles) from the likes of the AE86, RT104 (or whatever the model is), T-18 and a couple of others share the same ball joint as the KE3x
You'll need these steering arms from the said vehicles if you upgrade to the bigger diameter struts and the bearing plates (strut tops) from the KE3x
Strut upgrade also brings in a brake upgrade but what struts you use will depend on what type of brake upgrade you'll get. Have a search.
Stabilizer - as in the castor arm that goes from the radiator support panel to the lower control arm, it won't need to be changed.
Strut bar ? Thats one i'm not sure of