I am a EU citizen living in Australia, planning on moving with non-eu partner to the UK next year. What are our options?

[FromAtoB]

1. I am an EU national that lived in the UK from 2009 to 2016 (Bachelors, Masters & Work)
2. Moved to Australia in march 2016 - did NOT apply to permanent residence
3. I have been with my cohabiting partner (non-EU national) since 2013, and we have living together in Australia since march 2016
4. I plan on moving back to the UK next summer (june 2018) and want to bring my partner with me. As per EU rules, we will have been living for 2 years next march.

What would be the best way to go about this?

1. Should I (Or am I able to) request an UK permanent residence card from Australia (given that I was settled for 7 years in the UK), with the purpose of bringing my partner to the UK next year?,

2a. If this is possible, should we then aim for getting a residence card for my non-eu partner early in the year (before my resident rights "expire" due to being outside of the UK for more than two consecutive years)

2b. If this is not possible, am I still able to bring my non-eu unmarried partner with me to the UK? or would I require to gain residence again? In this scenario, I would ideally move back to the uk in may 2018 to "settle", and he would join me in september 2018

3b If this is not possible either, what would the process be? To request a residence card for my partner in my home EU country, and then move together to the UK?

I know we are still a long way but we want to weigh all options and minimise future inconveniences given Brexit.

Many thanks in advance!