It's also worth remembering the polar-pattern of the microphone and the acoustics of the room where it's being used.

The cardioid 104 will have the least sensitive area at the rear and a slightly broader pick-up - IE: a bit more forgiving if the singer moves the head in relation to the mic.

The super-cardioid 105 has the least sensitive area at about 120° and an out-of-phase rear lobe. The attenuation at the rear is about the same as 90° and the pick-up area is slightly tighter.

Personally I think you are correct in your choice of the 104 and I agree with Martin about the satin nickel version - the black may look a bit "heavy".

John Willett
Circle Sound Services - Location Recording
President, Fédération Internationale des Chasseurs de Sons
Chairman, British Sound Recording Association
Tech. Support, Sennheiser UK