There is a lot of choices doing Gui with C++ under windows, I propose FLTK (the most lightweight) or wxWidgets, they are both fast and multi-plateform but the second has more widgets and functions.
Relevant Skills and Experience
I have over 15 years experience in C++, worked mostly in Windows env, used Qt, wxWidgets, Fltk, MFC, I have experience in 3D dev using engines like urho3d, ogre3d, eyeShot, NeoAxis, OpenGl