If you use a discount broker, they should be able to offer...

If you use a discount broker, they should be able to offer purchase on international shares, although I can't help you here because I never have actually bought (or currently hold) shares on overseas indices. It is a bit more expensive, I believe Commsec is $65 a trade international versus the basic $29 / $19 domestic - depends on your arrangement with them.

iShares (listed in US) have a W8-BEN form, which is for the Aus/USA reciprocal tax agreement for foreign conduit income, although since BRK don't pay dividends (as far as I am aware), I don't know about CGT implications.