Can anyone recommend a solution?
If you can enforce a common column-naming / data-typing format on all of the Excel files, you have a chance of using SSIS and looping to do this relatively easily. It still won't be easy - largely because Excel does not enforce data types.
But if you allow them flexibility, your solution needs to code around that flexibility - a lot of work - and SSIS is probably not the right tool.
Help us to help you. For better, quicker and more-focused answers to your questions, consider following the advice in this
If the answer to your question can be found with a brief Google search, please perform the search yourself, rather than expecting one of the SSC members to do it for you.
Please surround any code or links you post with the appropriate IFCode formatting tags. It helps readability a lot.