Ok, this is just my opinion, but if you have never kegged or casked beer before, why would you want to start now? Especially since the pressure is on, and the people at the wedding who drink your beer will be the judges of its quality.
Sure, you may need to collect a ton of empties, and bottling a couple hundred beers might be tedious. But personally I'd stick with something you are comfortable with (bottling).
If you have ample time before the wedding to bottle condition your beers (about a month in bottle at least), that's what I'd do. However if you are pressed for time, kegging will be your only option to have the beer ready on time.