I think bar-end shifters tied to a mountain bike ratio drivetrain using a "low-normal" rear derailer is the best configuration (this makes sure that both bar ends pull the derailers in the same direction, defaulting to your lowest gear). Compatible parts need to be easily obtainable. Of course, this limits the 'ultimate' group down to a really really really narrow range of not all that pricey, older generation Shimano parts. Does anyone make a better mechanical disc brake than the Avid BB7?

The real bling on a touring bike, of course, is the frame, and then all of your gear- bags, racks, saddle... and having a job where you both get paid enough to own a fancy touring bike but also get enough vacation time to go rambling