Looks like you have some pretty good options, there. I've got a big canvas bag I call 'The Caboose' which could also take that stuff, but I don't see any more on Ebay.
What I liked to do for weddings and events is actually to bring two smaller bags, one of which would be basically-emptied, (usually the medium format body, flash, battery, and bracketry, also extra film and bits.) Then I could cache that bag somewhere and not have to be carrying around such a big affair all night, just working out of the smaller one. Not that you don't sometimes want a bigger bag, anyway.