a better solution for GUI in python

[ce]

Hi,

My company is using python currently for our website. We need to
develop a GUI front-end for our ERP that would be portable (Windows
and Linux).

My question is which solution would be better for the GUI (and easier
to implement)? I knew there are something like wxidgets, QT and pyGTK?
actually we will need some complicated stuff in the GUI and yet I
don't know much about GUI programming.

Any recommendation guys?