Adding drop down currency selector to woocommerce checkout apge

I am using the woocommerce plugin and paypal as my payment gateway. Right now you can only pay in USD on the website, which then tells paypal that the currency selected is. What I need is an option on the checkout page that is a drop down menu where you can select USD or Australian dollars (AUD). The price is the same in both USD and AUD, e.g. if it is 100 USD it will also cost 100 AUD, so no conversion takes place. However right now paypal can only be told to be paid in USD, and from paypal’s side it isn’t possible to have an option on their checkout page. What I want is a drop down menu at the bottom of the checkout page that allows you to select what currency you want to pay in. No conversion needs to take place, but I want it so that anyone who is in Australia will be able to pay in AUD and the paypal account will receive it in AUD (therefore no conversion will take place in our account.) You can see the checkout page after adding a product on [login to view URL]