Custom Upload for Interspire Shopping Cart 5.x

We have an eCommerce shop based on Interspire Shopping Cart 5.5 Our products are based on necessary files that have to be uploaded by the customers. ISC provides the option to get these, and it’s working well. We need a customization of the actual shop that allows to show up in a graphical way (progress bar, etc) the upload status of files and a custom text, remaining time to finish upload, etc This is meant so that the customer knows what is going on and doesn’t interrupt the upload process.