Thank you for writing.
We do not offer a "RadUserControl" in our suite set. For
accomplish your scenario, you should use the standard UserControl, add the desired Rad controls to it, and apply the desired theme. To apply a theme to all controls on a UserControl, you can use the following method:
Alternatively, you can use the ThemeName property of each control: http://www.telerik.com/help/winforms/themes-using-default-themes.html
I hope that you find this information useful.
the Telerik team