| Could never use just one lens ... especially if you were THE photographer there on the day.
Going on what is available ... the 16-50mm f/2.8 (if you can find a decent one without problems .... which is hard) ... and the 50-135mm f/2.8 are the ones I'd be using.
On a budget though ... I have a Sigma 28-70 f/2.8 and it does well for these types of situations. If i coudl get one though ... the Tamron 28-75mm would be my choice though.
Also ... a decent flash is needed for fill light on portraiture for wedding shots. |