Ubercart Multi-Currency Module be the solution for this project.
-There is an option to add new currency to the files. You can also import currency files also. May be currency Name , Currency sign etc. The format is straightforward & very easy to add new currency also.
-Also you can decide which selection plugins you want to enable to determine the actual currency used.
You can let the user select it (a Choose currency block appears among your blocks that you can place anywhere), determine the currency based on the current language of the site, link currencies to user roles, product types, etc. The plugin architecture is rather simple, so new plugins can be added with relative ease.
-Wherever Drupal presents prices (product prices, attribute and
options prices, etc) you will receive a replacement table instead of the original price specification fields that allows you to specify prices in all the currencies actually enabled and in use on your site.
Please let me know if you like this module. Please don't hesitate to ask me a demo of using this module. I will share demo.
I think you have an existing Drupal 7 website, where I suppose to customize the Ubercart. Please confirm it. In this case, please share the existing website. I need to check it. Have you any local set up of this website? If you share that, I will apply the module locally & check & will apply the module on live project.
Anyway, please let me know your convenience to have a detail discussion.