I got a UAI of 98+ in 2004 and I got the UWS Academic Excellence Scholarship and the UWS Blacktown CIty Council Academic Scholarship.
Both are $5k per year tax free over 5 years, so $50k all up over my degree.
They are just money payments, half each semester, so you can spend it on whatever you want.
Only conditions are that for both, that I achieve a credit or higher GPA each semester and that i don't fail units. And that should i not achieve the requisite marks, that I pay back the money for that semester.
Additionally the Blacktown Council one rerquires me to stay living in the blacktown council area.
As far as the Vice Chancellor ones go - they are 'leadership' scholarships, so unless you were a school prefect/captain, involved in SRC type stuff, charity work, community work or other such work etc you're better off going for Academic based ones. The VC ones essentially have the same academic requirements as the plain academic ones so if you have the marks to get a VC one but lack the extra curriculars, you stand a fairly good chance of getting an academic one.
Don't forget too that some are uni wide, some college wide or specific in some other way and you can apply for more than one (at least you could when i applied )