Short answer
None of that fits
 
Struts can't go in unless you build some towers for them to bolt to and set all the geometry
 
Brake master is the same as 1000 anyway as they both ran the same single pot master and drum brakes , unless its a late ute with twin pot master.. in which case you can use that and replumb the car
 
Diff is too wide
 
Steering is different too

Sure coilovers can fit. If you have the time money and fabrication skills. Have a look at what the japanese do for their historical race cars. I've seen photos of 1000'sthe with coilover setups.
But you will still need to retain most of the transverse leaf setup else there.
is nothing to hang the wheels off
In my opinion unless its a track car where every cornering inch is needed. The cost to get it all to work would never justify the marginal benefit

Just rebuild the existing setup. A transverse leaf system is more than suitable for the simple needs of a 1000.

Do you have any measurements of those coilovers or any pics
Im lost and cant remember if you also had the winters quickchange?
 
Just to answer the earlier question,
theres nothing wrong with 1000 suspension its proper wishbone
suspension, very light and beats any pogo stick suspension.
They have been raced in all circles with no issues whatso-ever

Looking forward to it!