You shouldn't be coming to Australia on a tourist visa with the intent to apply for a different visa on shore. To legally enter Australia on a tourist visa, you need to be intending to be a tourist. Entering on a tourist visa to apply for a different visa is sort of like skipping ahead--there are tons of people waiting for their offshore partner visas.
You can apply onshore with all different sorts of visas that allow you to be in Australia--student visas, tourist visas, skilled work visas, working holiday visas... but you should enter Australia with the intent of using your visa for what it was intended for. If plans change later, well, that's why they have the onshore visa.
Since you've contacted immigration already, I'd guess they'd be a little suspicious of your intentions when you arrive.