Purchasing a Phone - Best of The Worst?

I really need a new phone and I've decided on an Asus Zenfone 3 Zoom 64GB. Decent processor, RAM, storage and an awesome battery.

I've had Samsung's, and Sony's, each with their issues, so I'd like to try the Asus.

Seems there are few to no retailers of the Zenfone in Australia.

There's several sellers on eBay offering this model, all with seemingly poor after sales service according to eBay feedback and other forums. qd_au, buymobile, more_mobile, perfect_mission, big_yard, xcentric_mobiles, buybuybox(same as one of the aforementioned I think).

I contacted big_yard because they appeared to be in Australia, or at least have some presence here, and asked if they could provide an Australian Tax Invoice. They agreed. I was pleasantly surprised when eBay sent me a deal for 10% off Friday week ago so even being $100 more than other sellers, I bought the item, believing that I could claim the GST. Monday the excuses started about their ordering system not syncing. Tuesday they informed they had no stock despite their listing showing "More than 10", and still does. I got suspicious and started looking into it. From the invoice they sent me: The ABN was cancelled in April 2015. The business name "Tradeworkz" does not exist. The address is a Mailing service company. The phone number rings out. The mailing company said the business "Tradeworks" used to be one of their clients and thet sometimes get packages for them (perhaps return items?). I couldn't confirm if the they are related.

Thursday they offered a silver unit. I refused. Friday they returned my money. So that's a releif. Point is, they provided fraudulent information. I've reported all this to eBay.

A few other "Located in Australia" sellers that I asked simply said they could not provide an Australian Tax Invoice, so at least their honest about that.

So… Which of these sellers is the most likely to deliver what they promise and provide proper support if needed? Any better ones I don't know about? I'd like to take advantage of the 15% off that ends tomorrow.