Please Advise Regarding Itinerary Choices?

[In Retirement]

Greetings,

Its never too early to ask and learning from the successes and problems of others is a great value, so: Winter 2018 the two of us (then 71 years old) intend to take a Auckland to Sydney cruise with some additional time in Australia. My wife is determined to break the long flights with at least a 2-3 day stay in Hawaii and maybe something similar on the return flight. Anyone have experience in making such air arrangements, perhaps even a different airline for each direction? Would really enjoy a substantial exposure to New Zealand, but also for sure a stop in Tasmania and perhaps Melbourne. What have been your memorable experiences and what would you not repeat if you could help it? Our previous experiences have mainly been on Princess, Holland America and Celebrity and we see the ship as a convenient floating hotel room. Can anyone recommend a company for day tours out of Sydney or some Australian company comparable to Globus/Trafalgar for a several-day outing near Sydney/Melbourne?

DJ:)