I would urge you to reconsider SDL though - it's going to be a lot easier to port to other platforms, and it's going to be maintained for a long time.
e: You don't have to use SDL's audio/rendering subsystems either - it is possible to just treat it as a pure window/event management library.
https://github.com/ocornut/imgui https://github.com/cimgui/cimgui