It might be helpful to know what you are upgrading from...also I suspect a little background about what you hope to do with the gear would also be helpful.
I am currently using a Powerseeker 127, just getting into the whole deal and want to have a crack at getting some video and still shots of the planets. Getting sick of manual position changes so I am looking at a GPS attached to a drive motor and a reasonable telescope.
Still, learning so I will probaly only spend about $3.5k to $4k this time around.
Townsville has some excellent skies over the next 5 months and the weather is sooo good. Feel a bit for you down the chilly south.