We've got rello's at Parkes and they reckon the Elvis festival is great fun, apparently the arrival of the Elvis train is a hoot (their words) and the town just comes alive. There is a caravan park near the centre of town that looks quite nice although basic, I'll look up it's name later.
Only a short drive from Parkes you have Peak hill gold mine, Dubbo with the Zoo, jail and more, Wellington caves, and Forbes which has McFeeters motor museum (well worth a look in my opinion) and it's not that far to Orange and Bathurst.
We are trying to plan to stay out an extra week next year for the Elvis festival but it depends on the wife work.