Help with organizing 100's of photos from wedding shoot

I am looking for guidance on something, I'm sure there is an easy solution that will result in a forehead smack once I see it....  Here's what I'm doing/using, what's going on and what I would ultimately like to do...

After shooting a wedding, I am downloading my photos from (3) different cameras, so to begin with, the files are all importing within the camera subgroups. This begins the problem, in that the photos are not in order, they are grouped in order but by camera. I am using three different lenses but none are really specific to any given part of the day. I go through them, flag the keepers and ignore the throw aways. Once I am ready to start processing, I use the "flagged" sort option.

As I go through my workflow, I bounce between LR, PS and onOne. As this workflow happens, a strange quirk occurs....sometimes, upon returning to LR from one of the other programs, the new file and the original file move....sometimes to the end of the strip, sometimes to a random spot. Either way, I then unflag the previous version and keep only the most updated file. This step has now created yet ANOTHER mess of mixing the photos.

When everything is done, I upload to an online proof gallery. The problem is that my average wedding is yielding 400-600 completed photos that now look like a deck of cards someone threw across the room. The proofing gallery is not amused when I try to rearrange them after download, sometimes moving them as I want, other times, refusing to keep them in the order I am trying to create.....not to mention this is a time consuming step I'd like to cut out.

So....here's the question.....is there a process I can use in LR to group the photos (getting ready, ceremony, reception, detail shots, formals, etc) that I can then export in the order I want and have a proof gallery that is organized? Meaning, I select all the photos of bride/groom getting ready, export them then move onto the next group. Finished product being a nice organized list of photos in the correct order of the day.