That may well be the go, Glen. Your other option is to buy unmalted barley, and boil the amount you want on the stove in water to gelatinise it... (rolled barley is steamed before it's rolled to gelatinise the starches making them soluble).
Flemmings do all that stuff - they use it in their musli bars... hmmmmmmmm musli bar beer......
They have it in the Hutt shop too. The other place is Full o beans in Naenae.
The organic shop down ngaio gorge was talking about stocking it too - some time ago though - I haven't been back