I need to find an open source CMS that I can use for a voluntary group that is tied to Windows hosting which supports PHP and MS SQL Server but does not support MySQL. I would like to be able to use different design templates for different pages, so that the site doesn't look like a generic CMS if the client wants a re-design. I would also like to be able to extend on it if necessary. It should have a good editor that gives access to stylesheets. It should have role based authentication and the ability for admins to create new pages based on master pages and add content.