Henry Posner , Oct 21, 2009; 01:55 p.m.
I have a canon 430EX flash but doubt they will let me use it during the service (maybe before and after to photograph people).
Ask the person officiating the ceremony. Of all the weddings I've photographed and attended as a guest I think flash photography was permitted during the procession and recession 99% of the time and during the ceremony 80+% of the time. Some churches limit where the photog can stand during the ceremony.
A monopod will offer a compromise between stability and mobility.
If you find you're shooting by candlelight at ISO 3200 at f/8, maybe f/8 is the wrong place for you to be. While I appreciate the value of depth-of-field as much as the next person, you have two f/1.4L lenses. Bring both and plan on embracing your wider apertures. Accurate exposure is more important than depth-of-field OMO.