Have you tried Adam at Frank O'Gradys or the guys at Perth Swedish autos, also if your a member of WAVE on FB put a post on there, and look for a guy called Joel Cadlolo he's a bit of a guru on the P80's
Green injectors 850 FOUND
Not tried anyone local really as not on fb . Must get to the next WAVE meeting as it go's
I can get them new
https://www.ebay.com.au/itm/282587127853
I looked at those or similar earlier but apparently not compatible for 850 ..
- Edited
https://www.ebay.com.au/itm/6-X-GENUINE-BOSCH-42lb-INJECTORS-0280155968-440cc-GREEN-EA-EL-AU-BA-BF-XR6-LS1/114027964821?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
think this is what i was looking at but does not say for 850's

Same part number
Look at the part number. It doesn't say Suzuki gti but I run them there too..
I have a set of VXR 470cc injectors that used to be in my car before I upgraded to 550cc