visa requirements for Australians...

I have been offered a place in a tesol course being run in Harbin. I will be studying for a month and in this time they will try to find me employment in China. Can I enter on a L visa and then change it to a residents permit when offered work through the school. Would I have to leave the country to change visa's. Or can I apply for a Z visa if I get a letter of invitation from the school.