Don't know anything about Avondale but I reckon HVA are the go.
For background:
Cessnock has been, in the past, probably the biggest GA training airfield in Australia outside the capital cities.
The region is a major tourist area and although the city of Cessnock is not huge it certainly enjoys all the services and facilities. When I trained there in 1990 it wasn't exactly cosmopolitan but they are getting a bit more sophisticated in town these days.
It is only 1.5 hours drive from Sydney and about 45 mins from the coast and Newcastle.
Go for it!