Finding out information on Mk1 V6 Capri's has been interesting in part because of the conflicts in information on line. So I thought I'd ask here and get a definitive answer:
1.  Is there a difference between UK and Australian suspension setups? (ride height/damping ratio's)
2.  What strut inserts will fit the Australian Mk1 V6 capri's? - are they the same as RS2000 escorts?

oooooh!...spot the ex-pat!?
Apparently there are different part no's in an old Bilstein catalog for UK/Aust Mk1 Capri's hence the question.

I got some struts from the Uk, they had a larger dia thread at the top of the insert, the top spring seats are a different shape/height and have a larger hole, and the rubber top mounts also have a larger hole.
 
Monroe still do inserts for the Aus Capri.

UK 3 litre cars used the Granada struts.  Aust delivered cars all use the same, but, some early ones have odd sized tubes, Monroe give you a packing washer when you buy a new insert in case.  I assuming there were several suppliers back in the day (Armstrong Gabriel etc etc)

I suspect that you are right. I'm keen on a set of Bilstein B6 struts and dampers. I've used them before and they have a good reputation with the Escort guys. It's just a matter of finding the right set. The early cars seem to have an insert that is more lightly constructed compared to what I see on other cars. Also some online sellers list the same insert for 1.3-3.0 cars and good though they are, that is a fairly different weighted engine up the front!