Both can handle cufon. But it isn’t handled automatically, the difference is that the Pro version includes a way to doing it in the samples. You can do it too with the Lite version, but you’ll have to come up with your own set of functions to place on the onComplete event.
I need an option that isn’t available, would you implement it for me?
Maybe please send me an email using the form on the right side of the http://codecanyon.net/user/SurStudio page and I’ll see what I can do.
The difference lies on how many languages do you want to display (assuming you’re displaying their flags). In the Lite version, there’s an image file for every flag; and in the Pro version, there’s only one file with all flags (it also has single files for use by IE6). So the Pro version will be faster if you’re displaying all the flags, or the Lite will be faster if you’re displaying only a couple of flags.