Recommended Mobile Phone Services in Australia/Sydney?

Dong2016

I'm arriving in Sydney on Jan. 11, 2017 (IT professional) and will be looking for work as soon as I arrive. I would like to get some inputs about mobile phone services in Australia:

Which telecom would you recommend that has the following services:

1) Good overall coverage (like in Pinas where Smart has more provincial coverage and globe covers mostly city areas)

2) Unlimited call and text to other Au mobile phone and/or landline subscribers (need to make phone calls to recruiters and real estate agents)

3) Unlimited Internet/data with decent speed, if not excellent bandwidth (need to use internet heavily for online job applications and skype or viber with family back home)

4) What are the requirements to get a mobile phone (prepaid or postpaid), for Pinoy newcomers like me, considering I don't have a job yet, and will be staying in transient accommodations.

I appreciate any help.

Thank you.