I know Milland has quite a lot of genuine parts, not sure they all are though. Be very aware of the wording a lot of the people like Schmiedman, etc use, words like OE, OEM and "to OE quality" can be very mis-leading.
It depends a lot on how much the postage is going to cost, for anything that gets more than slightly large or heavy it adds up pretty quickly - even if you order multiple items at a time, and if you order too much stuff in one go you can get stung for the GST as well.
The US seems to be a good place to source stuff at the moment, good exchange rate and reasonable postage with no language barriers!