I'm not sure the 717 has the range for the HNL delivery path to Oz.
Is this the route they would take?
No, the regular 717 can't make it from SFO or LAX to even HNL I don't think. I remember reading all about how HA used the same fuel tanks on the main cabin floor from the DC-9 ferrying, except with the 717 it only took 4 as opposed to 9 for the DC-9. This was in the Airways a long time ago entitled "Boeing 717 Enters Service" or thereabouts.