Gc8-rally

Hi All I’m new to Subaru so please forgive the noob post but I have tried extensively to scour the internet and contact the manufacturers to no avail!
I really hope someone can help me.
My GC8 classic has been fitted with alloy front wishbones which I was told are from an “STI”
I have been told by a specialist garage that the bushes are shot, (which I can see) and I am planning to fit poly bushes
I understand there are two types of arms the steel type and the alloy but for the life of me no information is given to fitment when I’m looking for bushes.
I want to go for the flow flex because they are the cheapest - and I’ve used them before and found them to be great
https://floflex.co.uk/product/subaru-impreza-wrx-sti-turbo-1st-gen-front-wishbone-bush-set-2/

but they say
Notes I have is that our bushes do not fit 98/99 STI WRX R Version , will not fit impotrts or aluminium anti roll bars

even though they are listed as for STI. ? Or is the R version something else like a wide track?

I also have the dims of these bushes
Dimensions are for large bush.... outside diameter - 56mm total length - 57mm diamter between the 2 'shoulders - 40mm internal of insert - 20mm small bush in the same order - 37.6mm 53mm 43mm internal of insert 12mm



but without the arms off the car I just can’t tell.

I could just take them all apart but just wondered if anyone knew this

thanks in advance