I have aspirations to get to Australia / New Zealand in the next couple years as well. After reading all the horror stories of award availability for this trip, I decided to pick Ultimate Rewards point accumulation - so if there is no award availability I can always buy with points!

If you get the Sapphire (w/ 50K bonus) Freedom (has been as high as 30K) and Ink Bold (50K bonus) that is 130K points - before you factor in any spending. That would be good for about $1500 in airfare alone! Plus those three cards offer good complimentary bonus categories.