If I had to choose I would choose Snezhana although I don't find either one remotely sophisticated. And I say this as someone who was born in Eastern Europe. I find a lot of names used in that part of the world as dead common and trashy. And this particular one just reminds me of the English word sneeze. If this was my first name I would go by my middle one.
It doesn't work for me with a French middle name. The clash is jarring. I think it's best with another name that ends in A or a name that is the same in many languages.