I would say go route one. Might be longer but at least if something goes wrong your not stuck out in the middle of nowhere as bad as say driving up from SA.
9 days to drive 5000km's shouldnt be any problem at all. I drove from albury up to townsville and only took 3 days so you should be able to get there in no time at all. Just rcently had a mate drive from albury up to darwin and only took him roughly 5 days. Didnt push himself too hard or anything stupid like that.
Like R31Nismoid said, make sure you pace yourself.