Most Wii being sold in China are softmodded from Korean consoles ! 4.1C was a custom sys-menu in the district. [not my favor. :P]
If follow the "Softmod-Any-Wii" promptly in this Forum, you'll be fine.
for 4.1c or 4.1u, the differences are the Wii-SETUP menu language. The game language is not affected.