Welcome Wags
Great that you managed to keep the car, not many one owner Z's around.
$30K - $40K is solid budget number, is it enough ? obviously that depends on what is needed. How is the rust situation.
I agree, Ledge has a solid reputation and a look on his Facebook page https://www.facebook.com/CustomAndClassicCars/?fref=ts or his website http://www.customandclassiccars.com.au/ will show his work.
Another great source of restoration work is Lurch have a look at his Facebook page https://www.facebook.com/Classic-Auto-Fabrications-588753937823811/?fref=ts Lurch did my car.
One last thing - would be great to see photo's, maybe even start a build thread ?
Cheers
PB