I got My sill today. I ended up ordering it from netwarehouse AKA Restores hot Line AKA Rare Spares Adelaide.
They were great to deal with, very helpful.
I went to a sheet metal place the other day, but was told he couldn't get the radius on his bend to mach the ones on the sill. So I opted for ordering one already made.
I have to say it looks like it matches very well.