can u lend to buy foreign currency?, page-4

Thanks gents.

I have $70k in physical cash and an $80k Margin Loan with NAB.

I would like to potentially purchase $150k of USD or EUD when it hits a certain level, how can I do this and ensure my purchase is 100% safe, meaning I'd like to do it via a Bank etc, not some dodgy trading company that could fold potentially and then I lose everything etc?

Any ideas? Thanks!