Thank you for writing. You can consider our RadDock
control. It has a very good layout flexibility, rich customization features, and could fit well in your scenario. Also keep in mind that it had been completely developed from scratch for Q2 2009 release, so I highly recommend you upgrade to this version.
The other way to create an interface as the described is to implement it on your own, but you have to handle practically everything like events, interactions, and animations. I am afraid that this is quite an ambitious task.
Do not hesitate to contact me again if you have any other questions.
All the best,
the Telerik team