So, I have decided on my itinerary.
http://www.gcmap.com/mapui?P=MEL-SYD...PG-HNL-SYD-MEL
I booked VA MEL-SYD-APW (Apia, Samoa) with DL miles (great because I am trying to burn these). 22,500 for these flights.
The ferry/cargo ship option between Apia and PPG (Pago Pago, American Samoa) didn't work unfortunately because it only leaves Thursday night and I arrive Wednesday morning to APW. So I will book a flight. At first I couldn't find anything, but shockingly there is a 'city airport' in Apia, FGI. Polynesian Airlines and Talofa Airways both fly FGI-PPG. Both charge around $100 USD one-way and there are lots and lots of flight times and options each day. Of interest, you arrive 23.5 hours before you left because of the Int'l Date line! So I got one more day than I initially anticipated.
I then fly HA PPG-HNL, for 28k VA points. This flight costs $530 USD one way, so it's a pretty decent deal even though it is a lot of points.
I return HNL-SYD-MEL in J on HA and QF, for 65k AA miles.
So, a fair points outlay but I am in J on the return and I think it will be a fun trip!
I'm really interested in routing through other countries on FJ next time, and the interesting thing is you could even do that on a route to LAX. Although I do love my VA MEL-LAX direct, it'd be hard to give that up for a 3-stopper. A few days on a remote isle might make that better though.