Hello Kerry,
I used a prepaid world traveller card from CAXTON FX for my tour of Singapore, Australia and New Zealand last year. Never had any problems with it and it was loaded in Sterling (GBP). All I had to do if wanting any money was go to an ATM machine and draw out in local currency or pay for items, meals etc with the card in local money. Very easy to find balance etc from Caxton.
The Post Office money card would work in a similar way. I went for Caxton because the Post Office card is operated by Travelex and fees of 2.5% were deducted on every transaction were as Caxton wasn't. OK fees were taken by Caxton but ATM fees were free. They also offer prepaid cards in US dollars and Euros.
Hope this helps
Eric