E-Commerce Business Looking for postage costs review

We are an e-commerce business who will have products listed on various websites in Australia. Once ordered from these sites the products will be picked and packed at a fulfilment centre and then need to be sent to customers.

We require a report on the best postage service to use. i.e OZ Post or courier to see which method we will select.
For this we need to see how much our products will cost to ship to customers via different services and to different areas of the country.

We will provide you with the size and weights of our various products which can be used to find the cheapest service.