If your goal is to work with external tools to have them recognize and be able to work with your files, a better bet than JSON would be to use XML. This format is stricter (and you can use XML Schema to validate the format) and there are way more tools that are able to work with XML than there are for JSON.
The .NET Framework also contains extensive support for XML, in the System.Xml
namespace (see http://msdn.microsoft.com/en-us/library/system.xml(v=vs.100).aspx).
That being said, there is no reason why JSON would not work with C#. I have personally used the JSON.NET library for most JSON work and it works beautifully (see http://james.newtonking.com/projects/json-net.aspx). Mind you, the data you show in your example is not valid JSON.
Good luck!