As it is an 85 model ute all you need to change is the balljoint and steering arm to stanza items.

So you are using r31 struts now? I would have stayedwith the stanza struts or home bluebird ones and cut them down (then they are pretty much the same as r31 but you get more camber.
1200 and stanza springs are both pretty soft. 200b or bluebird rear springs are the right diameter and a bit stiffer.
Dont think the stanza struts will really be worth more with springs though.
If the ball joints and tierod end are still tight, you can just get new boots for them and regrease them.

You can't really do much fabrication till you have the inserts, as the spring perches will have to be moved if you go shorter inserts later