Getting Sudan visa
Hia, you can get your Sudan visa in Addis, in 24 hours all you need to have is an Egypt visa, if you have an Egypt visa then Sudan will issue you a 14 day transit visa, cost $100 US. You will also need photo copies of the visa, passport photos, and a photocopy of your passport along with your passport, they are helpful but the consulate is bloody busy everyday. Get their early.
You can get an Egypt visa before you travel or this is also available in Addis but took 3 days last year, also availabile in Harare. I am an Ozzie passport holder as well.