Alex's (icewolf) theater did the first non-for profit show in the US, or something, in the past couple months, and he was quoted in a, I believe, Live Design article about the fog/haze machine they used in said production. However, I believe that his theater does not have a proscenium arch.
I think the first question we should ask here, is why you need the pictures? As a general rule of thumb here on the booth, we try not to do other's design work for them, and encourage them to be original.
There are plenty of photos of the Broadway and West end productions of Les Mis on the Les Mis website. But, as if I remember correctly from the last national tour that I saw, there was nothing special going on on the proscenium.
If you are working from a purely research perspective then I would be happy to provide you with a link to photos from my theatre's production of the show.
So, let us know what you need and we will do what we can to help.
I've seen the national tour three times and it's never had any special proscenium. The beauty of Les Mis is it's appearance of simplicity... now as Alex I'm sure can tell you it's a lot of hard work making it look that simple. But there are a lot of scenes with VERY limited scenic elements.
So what are you doing? Like Alex said, we would love to help you develop YOUR vision for a show, or help you figure out how to technically accomplish it... but most of the people around here are very set in that it should be your vision. The Broadway version of Les Mis has been done already. Make it your own.