Ultalights,
In my experience dealing with councils and hangars on airfields, it seems that different councils have different policies on the subject.
One council on the outer Sydney basin gives only a five year lease with no option on the land that you lease, then require you to give over the building upon moving in, and then charge you commercial rent, rates etc etc etc.
Also, they have rejected various non aviation related businesses in the past, instead of utilising industrial with aviation (less noise complaints).
My advice would be to approach each particular council concerned and see what they have to offer with the land, but I believe that you may have to sub-divide to get a longer lease hold...... and as we all know, if you are going to deal with council and their gastapo tactics then you had better get your wallet out of your back pocket!
Sorry, brings back night mares!
Cheers.