Database driven Website designed (and possibly AJAX)

The company I work for has a requirement to keep track of people and large pieces of plant and also what these are being used to do (project costing) Currently this is being tracked via a fairly complicated Excel Spreadsheet with a large number of look-up tables providing the required data so that end users can only select/use the appropriate information in the appropriate sections. The sheet is by no means perfect (in-fact it's far from it) and can take considerable time to update the sheets and re-issue to the end users. We would like to move this data capture point to a MySQL driven website: * End-users would have various levels of access to the data/information (can give specifics on request) * Generate emails/reports based on specific business rules (i.e. Person is listed as "Sick" email to Payroll to process as sick-leave & also prompt for Site to complete a Sick-Leave form) * Export the Time-sheet data into XML format for upload into our Payroll system (XML Schema can be provided upon request) * Export the Job costing data into CSV format for upload into our Accounting System (formatting provided upon request) Ideally the data entry screens/areas would be as simple to use as possible (perhaps even mobile accessible?) to help the site based users complete these in the quickest/easiest manner. There are many other small features that are a "would like to have" rather than a "must have" and the final project scope will be negotiated based on what you feel is realistic. If you have any further questions regarding this project please feel free to contact me.