Given that selection I think I would use the two Leicas and perhaps have the F6 standing by in reserve somewhere.
It's good to have backup/redundancy in case something goes wrong and having two Leicas means you can swap between them instinctively without thinking about different techniques for working two different cameras.
My father used to use Reala exclusively for weddings as it was supposed to be formulated to give good skin tone whilst keeping wedding dresses looking white. However, the Portra would also be a good choice.
Having said that, I have only done two weddings - both unpaid, and I used a Mamiya RB67 with a Vivitar 285 flash and home made bounce flash adaptor.