I would recommend creating simple class that has properties Text and Value, for example, then create instances of this class and add them directly in the RadComboBox.Items collection. Set the DisplayMemberPath property to "Text". RadComboBox will display the value of the Text property as content in its items and the SelectedItem will contain the selected object instance. To directly retrieve the Value property of your object you could use the SelectedValuePath property, set to "Value" (the name of the property) and SelectedValue to get the value of the property, specified by SelectedValuePath.
Please, let me know if you need a sample application.
the Telerik team