whoah that guy is good. I just got the game, so I'm new to FPSes on the wii, but I can already foresee how sprinting / reloading / hitting any button that isn't the trigger will be time consuming and difficult compared to just holding the remote. --- "o"
If you're in the US and have a Five Below nearby get their cheap knockoff zapper for $5. The official Zapper looks like it would get in the way of pushing the buttons with that stupid dongle thing. The one I'm talking about is almost like a sawed-off shotgun. It's very compact, and fits nicely in your hands.
I recommend the Khan button layout. There's no difference between the remote+nunchuk layouts and the Zapper layouts except for buttons and gestures, so you can use either with or without a zapper. The advantage to Khan is that it allows you to melee with D-pad down and reload by shaking. That was big for me, because I was a big melee guy, amassing about 8,000 melee kills out of about 50,000 total eliminations. Meleeing with a gesture is dumb with a zapper because it makes your character whip his head around like an idiot.