Hi there,
Your requirements are quite clear I only need the fine details of matching process. As far as I can understand Salesforce integration will be handled through Salesforce API, let me know about this if that's not the case and some other method is preferred over API. Though not strictly needed, a sample execution of the tool from step 1 to 3 with actual files/data would make these all crystal clear.
Anyway, I'm planning to use Python2.7 to implement this. Still though if you have something else in mind like php, java, ect. that's just fine as well. I can start as soon as you award the project and expect to be done within 6 days.
Thanks
Aydin