Prototype of a GUI application based on .NET WPF

Hello, for our real-time finance applications we need a GUI. The idea is that this GUI is developed with .NET WPF as a standalone application and that a later point we convert it into a web application. We are looking for an experienced .NET GUI developer, that can provide us with the following/answer the following: - what .NET WPF widget library is the best (in terms of stability, functionality, costs)? - a installation file I can install on any Windows platform (other OS not needed) and that shows me some dummy widgets of the suggested WPF widget library (no functionality needed at the moment, just a showcase) - any update for the application can be easily deployed to all installed application instances (auto-update) - the web application that has been converted from this standalone application Hope you understand the above, we want to see if WPF is the way to go for this kind of GUI. Waiting on your bids Cheers