Can anyone help with some advice re visas?

We emigrated in November to Adelaide on a regional visa. We has never been to Adelaide before but were hoping to see it through for a couple of years before hoping to move to Sydney as this is where we wanted to be to start with. Unfortunately we couldn't get a visa for that so have the SIR 495 and have to stay in Adelaide for 2 years, work for 12 months.
As its a newish visa we're not even sure if we can move to Sydney after that?

What we would love to do is find a job in Sydney, get sponsored and move asap. Does anyone know if this is a possibility? There are so many more jobs in Sydney than here. Can we switch visas in any way, can we be sponsored by a company if we already have a visa here in SA? Do we have to wait until the current visa has expired? I can't seem to find any info on this -does anyone else feel the same??!!!

Lindsey and Wayne