As this has now alrady been answered, my apologies for being so closed minded (USA tunnel vision). I checked a site in AU and noticed the cost of a Firebox isn't exactly inexpensive. This said, I'd just suggest yuo choose any outboard audio processor (many from MAudio are also good and cheap) and use that. I don't have experience with the MAudio FIrewire Solo or Audiophile, but they seem reasonable as well.
Many good deals on Ebay to be found. These interfaces don't usually get banged around too badly, so a used one may be worth buying if funds are tight. In which case, I'd go back to my original rec of the Firebox.
However, I'm confused about what you're using these monitors for. Are you recording on the laptop? If so, what are yuo using for inputs?