Thsi is probably the best pic I have of the setup. I was going to snap some pics of the setup because I thought it was a pretty solid solution for just what you are thinking, but I guess I forgot. If you want I could mount some shifters on a bar and take a pic to show you what it looks like.
Here is another pic of a frankenbike I put together. It has cleaner looking cable routing...well for the shifters anyway. LOL