Australia runs on a similiar voltage as Singapore so all your appliance should work properly.
As the plugs are different all you need to do once you get there is go to any store that seels electrical bits and pieces and buy australian plugs then change them yourself. It is easier and safer then most people think to do it and saves you a lot of hassle. Adapter are dangerous and if used continuously can cause fires and or just fail to work.
My advice is if you are moving to Australia from here defiently buy new DVD, Big Screen TV's and the likes - Leave the in the boxes and use them their. It will save you lots of money and your new neighbours will be full of envy.
BTW make sure you by a DVD player that is unblocked to play all regions DVD's
