Zara,

to get an idea about total mileage use the online RTW calculator in the *A Website.

My RTW last year (starting in Austria) had China (PEK, PVG), Japan (KIX, TYO), Cook Islands (RAR via AKL), US (SFO) and Venezuela (CCS) in the itinerary, coming in just 100miles shy of 29.000.
Hence I assume you won't be able to include both Australia/New Zealand AND southern South America in your itinerary without passing the 29.000 miles.

For honeymooning I can definitely recommend the Cook Islands, though (make sure you include Aitutaki island!).
David