I want to customozie Wiki as an administrator with the following requierment.

User should be able to create their own content using Wiki. Once created that should be approved by the adminitrator to publish. Also

1. Users should be able to file their wiki pages under certain categories to make them searchable to other groups.
2 They should also be able to choose which of the other target audiences can see their wiki page.
3. Wiki pages will be divided into categories such science, IT etc.

Is this possible in SharePoint. Or do I need to create my own Webpart for this.

Please advice if I can use the exisiting Wiki as it in SharePoint 2010 or Do I need to create my own and how.

Thanks

karthick