HECS is a government loan for commonwealth supported places (assuming you are one), while fee-help is by a private provider. You can receive both but get ready for a BIG loan afterwards since you will have to pay back both the government and the private company you loaned from. HECS only pays for your degree, excluding accommodation and stuff like that. Also it is only available to government universities (Mainly the go8 universities). While the fee-help is I believe for all universities since the only eligibility for it is if you are attending uni. Also hecs, you only pay back the loan once you get a specific salary after your degree. Basically, depending how much you loaned from the government, if you say get paid $50,000 in your job, part of it gets back to the government to pay off your loan, while if you are earning too low, none of it will be given back until you earn enough to give back. Also remember that if you earn to little for the rest of your life (obviously won't happen), but if it does, the loan will then be transferred to your life savings account when you retire or to the next attendee you put in your will, most likely your children where they will have to pay off the loan. You know how the process goes for loans so I hope I make sense.
In the end, better to choose HECS since you don't have to pay it off until you earn a specific wage. While fee-help, no matter what you earn after graduation, you have to pay it off either way since it is private. However, if you aren't eligible to be a commonwealth supported applicant in uni and your application was denied and/or you attend a non-government university like bond, then fee-help is better and obviously your only option for a student loan in uni.
Studying post-graduate and undergraduate doesn't matter, as long as you are studying in uni that makes you a uni student.
Good luck with everything and hope all goes well.
