What you have to take into account that a good motherboard is also important. Epox NPA9+Ultra, the one I have, would be a good choice, cause it supports the higher speed AMDs, like the X2 4400, should I go that way. And it's not expensive, at least not here. I have no idea what prices are in Australia, but you might expect to spend more, cause you might need new memory. Will your old sticks work (or work well) with your new motherboard?

-- erlik