I found that there is a $150,000 Portrait Prize called the Doug Moran. You can go check out the website and download an entry form. It costs $50 to enter and $20 handling fee, but I think it’s worth a shot. You can check out past winners and stuff and get an idea. It’s the richest portrait prize in Australia. It’s based in Sydney. Google Doug Moran Portrait Prize 2010 and you should be able to get all the info you need!