Another option...
Use whatever you have relative to cogset. Change the bars but find compatible bar-end shifters. A lot of guys seem to like that set-up. It's not as nice as STI, but it's probably more durable. If you pork your STI lever in the mud, it's not going to like it. But a bar end lever is cheap and also in a location that probably won't get hurt in a crash.
www.sheldonbrown.com or
www.rivendell.com would probably be a good place to get levers.