OK, for the OP's benefit, I'm just gonna say that 10 speed is perfectly fine for touring.

If I had 10sp and was going somewhere ridiculously remote, I'd consider bringing an extra chain. All other parts I can think of will be just as easy or hard to get for 9sp as 10sp.

If you're considering barcons vs downtube, I'd go for barcons -- especially if you're going to tweak your gearing constantly. Much easier to use than DT.