List of available currency is located on download folder. and specifically for Indonesian Rupiah you can set to IDR, but it just a fake because Indonesian Rupiah currently not listed on paypal.
simpleCart.cartHeaders
No required any customize here.
2. Customize Background and text
This template is support for Advanced Blogger Template Designer and available for 3 customizations:
a. Body Background Color
b. Main Menu Background Color
c. Text Link Color
d. Blog Description Color
e. ShoppingCart Border Color
f. ShoppingCart Background Color
Now lets customize yor template color scheme, click Customize and you will redirect to Blogger Template Designer. You can see the option on screenshot below :