Hai friends there is only onenintendo wii emulator that is none other than dolphin emulator.
This emulator can also emulate GC games, the ROM size for this emulator is in very less size.
One minus point is that it cannot run on PC/PPCs with only intel graphic cards. Those who have ATi or nVidia graphic cards can download it from http://www.dolphin-emulator.com/.
For WII wad format ROMs just google them like this "game name wad file download". You can also connect WIImote and nuchuck and enjoy playing comfortably. HAve fun playing nintendo WII games.
The only Pokemon WII game is Pokemon Battle Revolution. The link for PKMN B R and DBZ BT 3 wad with emulator is this.
You can download in this page only.