A bit off topic here on the SFML forum.
First off I wonder why you think you'll need to get a better version of VS?
Also if you can't tell whether
SharpDevelop will fit your needs, how should we be able to judge? Just try it!
Anyways, I don't develop in C# so I wouldn't really know much.
Doing a quick Google search revealed that
MonoDevelop is suggesting to use
Xamarin Studio, which was bought by Microsoft earlier this year and made available for free.
Although it won't be free in the near future, you can apply for a EAP of
Rider, Jetbrains' new IDE for C#.