I'm currently facing a similar issue with Europe, specifically Suisse /Italy/ Greece.
Truckloads of info about, but mostly not including nitty gritty details like calls to Aus and calls to the sim from Aus.
Any guidance/ opinions ?
Have a look here: Communication & Internet
£2/day Vodafone UK is probably the best option you have, 25mb in some countries per day, 2mb in others. More info over in that part of the forum.