I study part time at Unitec and theres always heaps of off cuts/scrap in the skip bins by the fabrication shops. You could have a look there or I might have a look for you next time I'm there.
Perhaps any polytech that offers courses like that i.e. MIT, Unitec etc
I'm sure they won't mind you russling through their rubbish
Mr. T says "Don't do school, stay in milk, and drink your drugs"