You made very good time considering the distance you had to cover to get home! Well done. I was home not much before you, at about 10.10pm.
You should be OK with a camper trailer. Farm tracks for the trip through the sheep station country, north east of Burra. Dangalli Conservation Park is a place I have never seen, and hence the trip. Tracks through there might be a bit rough. I don't think there would be any sand up there, but we will see! Chowilla Game Reserve has a lot of clay. Not a problem if dry, but muddy in the wet. If too muddy it will be closed and we will use the Renmark Caravan Park instead.
Sunset Country is a mixture of firm, rocky tracks and quite sandy tracks with sand hills. But quite navigable with a camper trailer, provided the trailer is appropriate weight compared to the power of your motor. BEK from Melbourne had no probs with his camper trailer, but he did have a big 4.2 litre motor in his GU Patrol, and his trailer was on the smaller side of average.
I will find a few pics to show you what to expect. But bear in mind that the first few pics, north of Burra, were taken in February on a 40 degree day. I would expect there to be a lot more live vegetation in September, just after the winter.
I find this region area a joy to drive through for the rugged and isolated scenery. The Sunset Country is a lot softer on the eye, as you can see in the last few pics. And what the Dangalli has to offer I will be finding out for myself, as a first timer out that way.
I need to do some more research, especially regarding safety and emergency planning. I have a map I can dig out to find out where the repeater stations are out in the north east. and what frequencies they operate on. I will invite my mate Tiny along. He has an excellent HF radio and knows how to use it. He is a volunteer with the Australian 4x4 HF radio network. If he can't come along I am considering purchasing a HF myself. And then of course learning how it all works. Tiny will help me with this.