Yep, sounds about right. A 12m and 9m config on a twintip is a typical quiver.
You may need to re-calibrate your knots/square-metre chart in your head as Victorian wind tends to carry more punch than QLD's wind, as its colder and denser.
Thanks for the input everyone. Was hoping to be able to avoid getting another kite between my 8 and 12 but i guess ideally that would be case but of course, costs $$$$$
