Where to go C#,XAML or HTML 5

Hi,

I have a desktop application developed in VC++,MFC,SQL lite in VS2010. I am having following functionalities.
1) Audio
2) Video
3) Chatting
4) Contacts
5) Clouds

This is developed with 3rd party communication libraries which is developed in VS2005. Also thru C++ we are detecting whether device is attach or remove and based on that we create a thread and send some commands to the device and device provides us the response and we update the UI. This application will run only in Microsoft ecosystem.

Now the problem is I am not able to provide rich UI and thinking of alternatives that suits my application. I have following alternatives

1) C#,WPF,XAML, VC++ Managed Code (managed DLL)
2) C#,XAML,WPF --> Migration from C++ to C#
3) C++, WinRT, XAML --> This will run only on Win 8 (Metro style App)
4) C++,WinRT, Javascript, HTML --> This will run only on Win 8 (Metro style App)

Please suggest me which would be the best option that I can adapt.

Also if I want to make platform independent application then I can go for HTML 5, Javascript (WinJS), CSS. This route provide me to run my app on Win, Ios, Android as well.
But I am not able to identify what could be the problems I could face if I move from current development environment (VC++,MFC) to HTML 5. Whether HTML 5 provides any kind of API that will serve our purpose.

Can someone suggest what could be the right approach in order to achieve the above functionality.

I have gone thru several articles of pros and cons of HTML5 Vs C# Xaml. But I am unable to make out the which way to go.

Regds
SNI

Tags: C++, C#, HTML5, WPF