APG and SOCKET 478 Motherboards are getting rather hard to get a hold of these days down in Australia. Not many of the importers are wanting to touch Socket 478 for any more that just some of your entry level all in one MoBo.
Every one is going at least LGA775.
And getting a LGA775 with APG slot is still possible for now.
Like i can suggest some thing like a
Gigabyte 8IPE775-G Motherboard
GIGABYTE® i865PE+ICH5 Intel Pentium 4 Socket LGA775 FSB800 Discrete MB - 1xAGP(8X), AC97-8CH Audio, Marvell Gigabit LAN, 4 x DDR400 (Dual Channel), 2 x SerialATA + ATA100, 5 x PCI, 8 x USB 2.0, Hyper Threading, ATX
Howevever you will be needing a new CPU along with that.
You will most like be looking at at least AU$350 for both a motheboard and Pentium 4 2.6 LGA 775 CPU. Personally I would save up another $100 and get yourself a better CPU.
The only other suggest is that I can chase up some returned RMA stock from ASUS. However they second hand motherboard based on avalability. Therefore stock and getting warranty on them can be rather dicey.