There are a couple dates in mid-December that have availability in business class from SYD-MSP via HNL and DFW on a combination of Hawaiian and American. More like domestic first class between SYD and HNL but only 62,500 AA miles and under $100 in taxes and fees one way. For complex award itineraries you should always search for the long-haul segments first then add in the short ones. AA does not allow stopovers on award tickets anymore, but you could possibly get a stopover using other airlines with your Chase points.