Don't know if time is the issue,, but if it was me i would , head to port augusta , then take the roads through horrocks pass head to the clare valley , then the barosa valley ,, from there head over the back of the adelaide hills to handorf,, from there go down the fleruie peninsular to cape jarvis ,, then over the ranges to victor harbor , head to wellington ,catch the ferry and go through the coorong to mount gambier , , from there the great ocean road . ferry and on to pako .
Its not the direct route adds a bit on , but some real good riding roads if your coming through on the weekend , i don't mind hooking up and showing you part of the way to wellington