If you want to hear the score from Les Miz, stay away from these non-singers and get a cast album. The Original Symphonic Recording or the 10th anniversary would do.
I really enjoyed the 25th Anniversary Concert version from London.
I'm sure (or at least I'm willing to entertain the idea) that I'm missing out on something wonderful, but I know the plot of Hugo's novel, and as a source for an international musical-extravaganza hit, it seems a little less likely The Guide to Incredibly Communicable and Really Messy Diseases, but what do I know?