Maybe I can be of some help. I am a videographer, not a wedding one, but I have done a ton of live events that are very similar, and have done live webcasting. First of all, when you have your wedding filmed, usually they have multiple cameras, and they take their tapes, bring em back and edit them together. The problem with this is that the cameras are not feeding into anything like a switcher to mix the cameras live. So even if you hooked up a live feed to the web, you could only have one camera going out, unless the people you use for your wedding actually know what they are doing and have a mixer that would send out a signal from their switcher to the web. I think your best, and most cost efficient way to go about it is to get your final edit and upload it to the web. If you have any questions, let me know, this is my profession.