Every RadPanelItem has a property named Attributes, which contains all public properties of the RadPanelItem as well as any custom attributes added to the inline definition or in the XML content file.
Using the <%# Container.Attributes["Name"] %> syntax you can use single template in multiple Items and together with the simple data binding you can assign different content inside the template content.

Please note that you need to manually call the DataBind method on every root level panel item in the Page_Load event handler.