Overseas web hosting providers can be very attractive in pricing and resources but if your main target market is Australia, it is recommended that you also host your websites in Australia.
Here are some of the benefits:
Response times on a server is is affected by your connection and the connection provided by the provider, majority of the time both connections are pretty consistent. in their latency. The other major factor that affects response times is location of the website server. Having servers overseas will affect performance and responses time due to the latency. The chart below shows the average pings to server location around the world from Sydney. As you move further away to another country, the latency increases. To get the best response times, hosting in the country where you customer is your best bet for the best response. No one likes a slow website.
Support is hard to come by and when support is mainly overseas, who can you call or email when in need. Our support staff and account managers are located in Sydney,Australia and are ready to provide support when needed. Our preferred suppliers who provide 24/7 support are located in Melbourne and are available when we need them the most.
All your data is stored on Australian servers. Overseas server may have unnecessary international policies which could provide some headaches. Save stress and avoid the headache of unnecessary international policies.
Server IP and location plays a very small role in search geo-targeting but if you decide to locate servers overseas it is best use the webmaster tools to specify location and the domain name extension (.au) to let users know that you are targeting Australia. Source
For the best user experience and response times for your users in Australia, it is best to have your websites located in Australia. Getting a hold of Australian support is also a massive plus.