Synchronize xml tot mysql

Needed: One or more php classes that synchronize a productdatabase in remote xml-files to a mysql database. What I have: - xml files on a remote server, that contain the data of a product-database. One xml file is an index-xml file, with created- and updated attributes, and links to other xml files. - 21 empty mysql tables What I need: - One or more php classes that fetch the remote xml files, parse the xml files, and checks what data needs to be inserted/udateted/deleted in de mysql table, in an efficient and safe way. The class(es) will have to run once a week, and: - compare the created- and updated attributes in the xml files with the created- and updated fields of the mysql tables, and only fetch data from the xml-files that has been changed - delete data from the mysql tables that excists no longer in de xml-files - update data in the mysql tables, if the corresponding data in the xml fields has changed - insert data in the mysql tables that is new in the xml files - the class(es) need to check if the remote xml files are available before data gets modified in the mysql tables(otherwise the mysql tables wil be emptied if the xml files are temporary unavailable) - images that are referenced in the xml file needs to be inserted/updated/deleted in filesystem specifications of the php code: - the class(es) needs to be a inheritance of Pear’s XML_Serializer specifications of the platform it needs to run on: - php 4.x - mysql 5.0 - apache on windows 2000 Part of this project is to find out which xml field corresponds to which mysql table- and mysql field. Good understanding of English is necessary. It is possible that de mysql dump contains more fields than there are fields in the xml. Only the information that is available in the xml needs to synchronized. Please give an indication of the time you need to finish this project