There are simply too many variables between now and when you want to travel for us to provide any meaningful responses.

If the bulk of your miles are with a *A carrier, then you will need to ensure that you can transfer them to EK (at present only UA, CO and SA are EK partners. You will also need to join Skywards prior to doing this. You mentioned you wanted a combination of fare+mileage.

You will need to ensure that you have enough for a one-way upgrade from DXB-SYD (ie 45,000 miles for one-way on a flex ticket).

Because you don't know what fare you will be able to buy yet (ie flex or saver), then it also makes upgrade planning harder. For example, the system currently doesn't allow upgrades from DXB to SYD or MEL on anything but a Flex Fare.

If you don't have status with EK, then redemption is also going to be difficult (ie EK elites are able to upgrade on-board). Not impossible, but difficult.

At the end of the day, if you want to sit on the big Bird, then most carriers such as EK, SQ and QF are maintaining their premium price point for the premium cabins, as there are no shortage of people wanting to fly them. The novelty may wear off in a years time, but who knows what the air travel landscape will look like then, what competitive forces are at work and what the state of the economy will look like.

Hang around the EK forum for a few months. You'll get the answers you need eventually.