Well I think title says it very well, how do you think, is it good option to make program with GUI?
Any of the .NET languages would be a good "option".
It might be easier to start it in VB or C# and do the back-end assemblies in C++.
Don't forget you can actually program in C++ and .Net at the same time :) There is no reason to switch between VB, C++ or C# just to make a GUI.
I have studied C++ for like 7 months soon and have created nice programs including little 2d game with clanlib, should I go with visual C++ .net? :P
If you stay in the .NET world, you will want to learn C#.
If you have the time, why not write it in both languages?
I was a DIE-HARD MFC programmer until I ran across C#.
I still have lots of legacy code in C++ and when it needs to be enhanced, I will flip the /clr flag and add a C# library to it (calling it from C++).
Try something small at first in each language, then decide.
If you're in a hurry (and have 7 months experience), stick with C++.