Hi Ian,
The Tradestation sign-up process is legit, but it cannot link a bank account in Australia, even if login and password are provided, so it's better to skip that step if possible, or do it and then change the password.
After the sign-up process, the user will be able to login to a Tradestation account management (it's different to a trading login) and check the correct deposit instructions. There are SWIFT and other required codes to transfer the minimum of $2000 USD to the Tradestation account to activate it.
Once the minimum transfer is made, it is possible to download the Tradestation software which will "lock" to the computer where it is first used. Additional computers will require authorisation by calling Tradestation (this part I haven't tried).
Best of luck,