I agree with Sam that PayPal
www.paypal.com.au is good for you. It's like having another bank account. You can transfer from that account to your regular account whenever you want, or just leave it there. PayPal has a small charge per transaction, but it costs nothing to set up.
You can advertise your prices as whatever currency you wish, and the credit card companies do the conversions for you. You can also block certain countries from purchasing if you can't deliver to them.