What would be the best framework for XML/XSL/XSD/XHTML app with PHP

Question

I am in the process of designing a web application that takes HTML form input and validates against XSD files and eventually stores data in a Database. I am looking to use the LAMP stack for this application and am looking for ideas on what framework(s) to base my application on. The following are my requirements:

• Web Application with heavy Ajax usage for validation of user input
• Input needs to be validated against XML Schema
• Ideally, I'd like to generate the HTML forms from XSD
• Uses a relational DB like MySQL
• Generate PDF
• User accounts - registration, login, etc

Thanks in advance for help!