Robin Pen. Been a long time since he programmed a con, but he's rather good.

Beyond you three, I don't know of anyone else in Australia I'd ask to program a WorldCon. Dave McDonnell was a fabulous choice for A3, but had to pull out for various reasons, and since I'm not in contact with him, I have no idea if he'd still be suitable or up to such a task.

I could probably muddle through it to produce a serviceable WC program, but only because I know good people I could ask for suggestions and advice.