oh thought i might give an update. thanks for all the suggestions though. I've chatted to the excavation guy who needs to clear some firebreaks for the burnoff and he has an attachment for his excavator that he made that can tear out heaps of blackberries and all the top layer of scrub and he was actually surprisingly affordable.
All up to get the fire breaks done, a pond dug out, trench dug for an over flow pipe from the tanks to said pond, and a stand done for another water tank was only gonna cost like 1,500 bucks so I reckon i'll get that guy to come in and clean up the rest of the shit at a later date.