Hello,
I see two big phases in this project:
1. Getting all of the expense reports into a structured database / file (ETL process).
2. Creating the visualization based on the database built in step 1.
For the first phase, I have plenty of experience with web scraping which would allow me to get all PDF files corresponding to the reports, and from then I'd either manually or hopefully with a script get the data.
For the second phase, I've got experience with Tableau Desktop versions 8, 9 and 10. I'm confident that I can provide you with a nice report to be embeded into your website.
Looking forward to working on this project.
Thanks,
Derick