Maestro - Darkside vs. Fellowship is a bit ambiguous. But as Dark_lord said, if it's the sith from the heydey (like in Knights of the old Republic), the fellowship couldn't compete.
But we'd have to setup neutral territory and I don't know how that can be. Would lasers work in middle earth? Would the force work? And, though I pitched this idea to Peter Jackson, I don't know if Hobbits In Space would work either. And we never really know the true extent of Gandalf's power, or even Aragorn's... I feel we have a pretty good idea the limits of the Sith.
OK, I am going to go drink whiskey and hit on girls to counteract the nerd blood coursing through my veins right now.
Oh and Dark_Lord... your math is a little off with the dark side > LOTR
But I don't want to war with you. We'll let it go.