Hi.
I am an C++ / Qt developer. I have an experience in creation GUI for desktop and mobiles.
I am not familiar with ballview but I searched the web a little bit. It seems BALLView supports different platforms - Mac, Windows, Linux.
I guess, that Qt will be better choice. You can port your application to other OS in the future.
I have a such experience - running the same Qt app on Linux and Windows.
And in most cases it is nothing to port. Properly written Qt application runs on both platforms (in case no OS specific features used) . Just need to compile it.
A few questions.
What Linux distribution you keep in mind?
Do you have a some GUI layout for your application? Maybe some specification?