You can use MS Expression Blend to extract the styles and Templates you need. You can also get them from the Themes subfolder of the installation folder of your RadControls. The RadButtons use internally ButtonChrome control and you probably need its style too. You can examine it in the attached solution.
Best wishes,
Petar Mladenov
the Telerik team
Register for the Q2 2011 What's New Webinar Week. Mark your calendar for the week starting July 18th and book your seat for a walk through of all the exciting stuff we will ship with the new release!