Congratulations on your engagement! Perth is a lovely city to be married in and I am happy to help with your planning. There are many beaches, our Swan River, gardens and parks that would be spectacular to be married at. You can even get married at my Home-office if you would like.
Anyone can be married in Australia, as long as you are over 18 (or if under 18 you can get permission from parents and a court), lodge the Marriage via the NOIM at least one month and one day before the wedding, prove to the celebrant who they are via Original Birth certificates (or overseas passports if born overseas), prove you are not married by showing the celebrant original copies of the divorce or death certificate.
Then at the wedding you will need to say your compulsory vows, I will say my authority and this is witnessed by 2 witnesses. The documents are then signed and I will register your marriage with the Registry of Birth, Deaths and Marriages. I have a vast catalog so we will together write a ceremony that will suit you both.
In regards to lodging the marriage via the NOIM, this can be done quite easily from an overseas country. I will help you with this and all other parts of the planning process. As an experienced Celebrant I will make sure all aspects of your wedding from the moment you contact me to the actual wedding day run smoothly for you.
Also if you need a Fiance letter for immigration purposes I can write this for you too (once the NOIM has been completed and lodged with me). Just ask me when you call or email.
You can also have a look at my video on YouTube: