Long term collaboration - PHP/MySQL - manager for the theme / css of our system

This project is on some managers for the theme system for the e-commerce shop, with these features: - separating the loading of templates from the css (now the system use the same name for template folder and css folder) - creating a manager to select and edit the templates (that decide the layout, so 3 cols, 2 cols), with a preview of the result. - creating a manager to upload a css, edit and apply it (again with a preview) The budget for this project is 500$ IS REQUIRED THE KNOWLEDGE OF: - SUBVERSION - PHP 5 - MYSQL - AJAX IS PREFERRED THE KNOWLEDGE OF: - SEAGULL FRAMEWORK - PROTOTYPE / SCRIPTACULOUS (for css/javascript stuffs)