Depending on your paid ticket flying patterns, I find that Oneworld miles are much harder to accumulate than Star Alliance miles (using Aadvantage and Mileage Plus as benchmarks), so in that case your 60k OW miles may be worth more than your 75k *A miles.

Having said that, the choice for me would vary much on the equipment on the routes you're looking at:

For your *A option, SQ has a couple of different configurations for PEK-SIN and also for SIN-AKL. Both legs can be on the 77W which would be a treat but require an overnight as the 77W flight from PEK comes in after the 77W flight to AKL leaves. CA also depends heavily on the route, if it's a 77W route then business class is quite ok, but CX would still be better.

For your OW option, I think you can't go wrong, equipment seems to be good on the longer flights but SYD-AKL will be nothing special as most are on a 738 with a 'domestic first' type business class.