You will get the best exchange rate from a credit card. You can usually
withdrawn from an ATM using you debit card (if not try a different ATM), but
your will pay a service charge (with CIBC it's $3 CDN so it makes sense to
draw out the maxium amount). I was in NZ & OZ for a year and having a
couple hundred dollars in cash and a credit card worked out very well. I
used my credit card whenever possible and used cash when it was more
convenient.

Dwayne