one step ahead whoosha. i was going to link him to the pics in the truck thread.
i wouldn't plan it too much unless you get in a situation where you really need to push on to get somewhere. the 6month old may dictate when and where you stop, and sometimes whether you'll even set off again or just call it a day a bit earlier.
i have 2 girls (as you know) and have travelled when they were each 6 months old. Emily was a breeze. stuck the dummy in and she'd sleep for hours. chelsea has never taken to the dummy so the trip we did when she was 6month old was murder. she wouldn't settle. wouldn't sleep for long periods. would cry as soon as you went to put her back in the car as she knew what was coming. it gets to the stage when not only is the 6month old yelling but the wife is having a go as well. all the while, you're trying to drive!!
the trip to perth by road is one box i would like to tick as well so you'll have to fill me in when you get here. i might even be able to tell by looking at you how it went