I'm a fan of the Gibb River Road in northern Western Australia, it's around as long, has some beautiful gorges along the way for a little swimming, there's a river crossing at the Pentecost.
There are a few campsites along the way, and there is fuel at around the halfway point, and a town at each end, so it's not quite as far from civilisation as the Trans-taiga, plus you don't have to drive back the same way to get out! It's also significantly warmer, so much so that you want serious sunscreen and bugspray.