Thank you very much for your interest in GroupDocs and for your time.
Yes, our GroupDocs embeddable viewer can be used to view document with all you mentioned formats. We have viewer plugins for several .NET CMSs: DotNetNuke, Orchard, etc. The list of supported CMSs you can see here http://groupdocs.com/marketplace/plugins. In GroupDocs Viewer we have a functionality to enable or disable file downloading.
Please notify us if you need any other information or if you need a call. Someone from our business team can contact you by phone if you would prefer this.
Vipin Thomas, GroupDocs Support Team.