We are an team that are dedicated C#, and will start with an new project, there the customer really wants it in VB.NET.
Are there a bad choice to do the development in C# and then convert it and deliver in VB.NET.
Are there any tools that will make this easier to us than any simple converter?
I wouldn’t recommend using a converter for a whole project. They’re OK for code snippets and perhaps a class at a stretch, but even with two languages like C# and VB.NET based on a common runtime there’ll be things that can’t be converted.
As I see it you have the following choices:
Convince the customer that writing the application in C# is for the best – it’s the language you know and you’ll be able to deliver a higher quality product in a shorter time.
Write it in VB.NET, but point out that it will take longer to deliver.
Don’t take the project. I’m assuming that this is not an option, but I’m including it for completeness.