Have a good look at what is available for the Flex viewer. It is far more developed with more tool (add-ins) available. The Silverlight viewer examples are not of much use unless you can really program. If you would like to stick with Silverlight, and your require lots of customisation, rather use the Silverlight API and develop your own framework and tools. There are some example frameworks and the other examples might be able to work within your framework. Be aware that different design patterns are applied in the various examples and it is not very consistent. You can also try using the code of an older framework (version 2.4) and upgrade it to 3.0 (but then again that is also not straight forward)