Might be a job for an exhaust shop - they're not popular cars in Australia.
I had a turbo back exhaust done on my TDCI Focus by a local exhaust shop, 3" turbo back with a single muffler was $1000 drive in/drive out in mild steel with mandrel bends.
https://focusonperformance.com.au/3-...deo-xr5-turbo/