You'll love it, my favourite country to fly over is the outback stuff.
Being summer, and if you don't want to be tossed around I'd get going early... as it'll get rough and hot as the day heats up. Once you leave Emerald the Navving to Longreach is a piece of cake! Pretty much just follow the highway. Enjoy the different scenery and cattle stations you'll fly over. There's airstrips at a lot of stations if you run into dramas, or just want to drop in... buzz the strip or homestead first. Don't forget about DA with the hot climates.
Check out Barky airstrip, it's huge!! (just east of Longreach). And be aware of the blackness if you do any night flying, but you'll find Navigating quite easy as you just head towards the town lights! If you take off in the dark, look at your instruments and not the black hole out front! (much different to flying from the coastal/built up areas)
Longreach is a great place, and you'll see it from miles away, as the 747 sticks out like cowboy in a city. If you run into any trouble let me know as I have a contacts spread all around that area. There is a little restricted area just south of Longreach about 10-12nm from memory, just to be aware of. If you have the time, head home via Windorah or Quilpie, the channel country through there is awesome I reckon! Avgas is available from Windorah but not Quilpie from memory.
Enjoy your time and let us know how you go... I miss that country so much now that I'm down near Sydney....
Here's a dodge video I put together a few years ago.