4.1 is the best choice for you. Others versions like 4.2 and 4.3 were created to remove hacks.
As your Wii was forgotten, then use ModMii and update its IOS and cIOS to new games and compatibility.
ModMii: http://gbatemp.net/t207126-modmii-for-windows (use Wizard mode and say ur Wii is Virgin - stay with urs SM 4.1)
Dont forget thx to XFlak