The 'conventional' path to do that would look something like this:
OW (18m)
AOW (with Deep speciality, 30m) & Nitrox
[Drysuit speciality]
[Rescue Diver]
[Twinset speciality]
Advanced Nitrox & Decompression Procedures (45m)
[Extended Range (55m)]
[Normoxic Trimix (65m)]
Advanced Wreck
...with the () being the certified depth (may vary slightly according to which agency you take the course through - typically PADI, SSI etc for the Rec courses and TDI, IANTD etc for the Tech ones) and the [] being 'optional' ie non-mandatory courses (depending how deep you want to go ie which sites)
You should rack up 20-30 dives minimum between each course, to practice what you learnt in said course. Several of the courses have minimum logged dive requirements (in certain depths/conditions for the Tech courses)
You could choose to go the GUE/DIR route but since they don't currently have an Advanced Wreck course you'd have to crossover at the end and/or hope they do have one by then
Meanwhile you can dive the HMAS Canberra at OW level - no penetration obviously - and also the George Kermode. THe other shallow wrecks like the Eliza Ramsden have mostly fallen apart now although can still be good dives, as well as all the other great sites inside the bay like Lonsdale Arches. The J4 can be done at AOW level. The deeper subs & other wrecks will still be there in a few years when you're certified
