I no longer know the stops in NSW it's a long time since I did that stretch but as far as I'm concerned the best and easiest places to stop for fuel.
Renmark,
Port Augusta,
Ceduna,
Border Village,
Caiguna,
Norseman
They are my stops which I can comfortably do without running our of fuel, even towing a van those fuel stops shouldn't be too far apart.
As for stopping over night probably I'd probably choose Ceduna over PA and I've never stayed at Caiguna. But if you're only doing 450ks a day I'd suggest you'll be looking for pull off areas of which there is plenty. Some pull off areas even have water and will fit many vans so there is no reason not to stop there if that's your choice. Most of the fuel stops also have space for vans too so if you want food, a shop and maybe some playground for the kids they are an option.
The only places I refuse to stop these days are Mundrailla (very little but bio fuel), Cocklebiddy (the staff are rude and arrogant) and Nundroo (the locals are too friendly at times). Also despite what some maps say you can't rely on Yalta as it's been closed now for about 10 years and as of last year still didn't look like it was opening.
But casually doing 450ks a day and you'll see a lot of little towns between PA and Ceduna and many little tid bits a lot of other people don't see.