324059 interactive web mapping api

I need to build an interactive web mapping application using either google maps api or ArcGIS server javasript api/silverlight/WPF. Here's the basic idea. 1-User will be able to manage(insert,edit,delete) points, line, polygons in database or datafile 2-That data will also viewed in a table(gridview or datalist) with edit capabilities 3- Simple reporting capabilites in a printable formview with map of selected area included. 4-User will be able to utilize real time online datasources via rss, xml, csv, kml and toggle between them while using the map interface. 5-Create cascading dropdowns that will allow user to run multiple queries and view the results in mapping interface. Requirements: Needs rich interactive looks and feel. Incorporate floating panels for the queries and map interaction tools(zoom in and out, pan, etc).