Call Jap / Suby wreckers all over Sydney and see what you come up with. Also, try eBay and Gumtree. You should be able to find one for relatively cheap (sub $1k).
I know this is a Foz motor, but presume it'd be similar -->
https://www.ebay.com.au/itm/subaru-fore ... SwD7dbDeA8Gives you an idea the type of price these N/A motors go for.
Sorry, just noticed you said install too ... that'll set you back a bit. Do you know anyone mechanically minded that could help you do the swap?