Why dont you just register a business under just your name, and then when it takes off or you have made your fina decision register a trading name.

My business is just my name... Didnt cost me anything this way as i just applied for an ABN under my name and then i automaticaly was registered as a business and a tranding name...
if it gets bigger then i have a new trading name and actually pay the fee then

Your website can have any name as long as when you invoice you also include your name and the ABN as well as what the website is called

HTH