Most people hire baby capsules from the Red cross or try 'hire for baby' . I have a 3 month old baby and didnt like the look of the standard capsule seats as they look like buckets. I hired a baby seat that looks more like the ones used in the Uk. It just has a base that is left in the car.
There are always sales on in one shop or another.. such as Target or Big W or Kmart for car seats, so look out for one when you arrive.
I bought 2 car seats with me when I travelled with singapore airlines.. it wasnt weighed as part of my luggage allowance, but check with the airline..
if you need any baby equipment when you arrive, you can hire most things from cots to high chairs from;