A friend is lucky enough to be posted Down Under for a couple of years - getting to take his family with him -- some special needs involved and special appliances.
He would like to have a converter for mains power - to 10A at 120V - to 60Hz.
You beat me to it Phil I deal with Jaycar Electronics a fair bit for our Truck CBs,reversing cameras ect I can spend an hour just wandering around their stores checking out the all the gear
This works for electronics, which have their own internal power supply. For devices with motors however, the 50 Hz power can be "poisonous" to motors designed for 60 Hz.
And that was the intent of the question: a power supply that not only steps down from 230V to 115V or so, but also puts out that power at 60 Hz.
Many commonwealth countries that use 220, have step down transformers available to buy pretty much off the shelf, I understand. They come with a variety of plug adapters too. I bet you could find them in the duty free shops near and in airports, but wouldn't be surprised if they were to be found at any retailer in populated towns too. If frequency is important, it gets more sticky, but there's bound to be something.
I suspect that the power may have to be converted to DC and then back to AC in order to change the frequency. That would, I imagine, be a considerable bit of gear. @DEcosse would know a lot more about that sort of thing than I would though.