Some of the other towns we stopped overnight at were Narrabri, West Wyalong, Coonabarabran and Gilgandra. All those towns had nice motels to stop at, but not much to see. Moree was the furthest we made in one day, that was a hard drive for my dad but only 400kms from Brisbane so made for a really easy drive the next day.

This website has a great map...
http://www.coastshop.com.au/maps/3melbourne_brisbane_map.htm

ETA: there's the satellite dish at Parkes, that's interesting!