Thanks guys. I have thought of shifters just haven't made up my mind. I was thinking of something more up to date but I understand that those systems can be a little tougher to fix in a pinch. My Di2 system on my Super Six would not be a good fit. I am going to install the shifters on the down tube, I like that idea. Since there is a place for them to be mounted it just makes sense. I don't want bar end, down tube it is.
Having ridden quite a lot with downtube shifters in the past, I recommend that you reconsider using them for a touring bike. They are reliable and precise but about as inconvenient as you can get if you need to shift in a hurry because you got surprised by the terrain. Barends are better but not by much. Brifters are, by far, the most convenient shifters but, as you note, can be difficult to impossible to fix if they fail.
So, an alternative: Check out gevenalle.com (formerly Retroshift). They make brake lever mounted brackets that come with mounted shift levers (or accept your own downtube levers or barend shift levers) and are available in 9,10 and 11-speed versions and with brake levers for road/cantilever/road disc or V-brake/MTB disc brakes. These levers also offer a friction option for rear shifting in the unlikely event the indexing is a problem due to damage, etc. They offer the convenience and rapid accessibility of brifters with the durability and low replacement cost of downtube levers. I have them on three bikes, two 10-speed and one 8-speed, and for convenience, cost and reliability, would never go back to anything else.