Darren,
A couple notes on your trip:
- the LHR-MEL route via SIN is only served by QF. BA metal no longer goes anywhwere other than SYD and BNE in Australia. If you went to Perth first you could take CX via HKG to SYD and connect to QF 63 from SYD - PER that offers a First Class service during the Aussie summer. make sure you take advantage of the spa in HKG.
- AA will no longer serve ANC from SEA. I believe service ends Oct 31. They will serve ANC for DFW in the summer however.
- Many of your choices (SYD-PPT, HKG-BOM) do not offer First, which with all your flying will be quite uncomfortable.
Also, why do you want 100K base miles??? If you are flying First 66,667 base will still get you AA top tier status.
rich