You could make it localizable. Implement a region specific icon and use the local currency symbol. Then changing the symbol to the right currency is just another step in translating the app.
It may still be interesting, if this should depend on the language or region setting, though. I am not sure, if a European citizen currently being in USA want to have a ...
My task was to create an icon/graphic used in an e-commerce checkout process...
The problem with the icons you've considered is they look like they could refer to a spreadsheet report generation tool.
Most shopping sites now use a shopping cart icon to refer to checkout.
There is a universal sign called Currency Sign ¤.
The symbol was first encoded for computers in 1972, as a replacement for the dollar sign in national variants (ISO 646) of ASCII and the International Reference Variant.