Cantilevers are probably the most popular option for touring bikes, particularly if you use road levers. Other options include discs, and Vs. VS require a special lever or dingus to work with Vs, and these products reduce the leverage of the combo so there is not always a net advantage in stopping power for VS with road levers. Some people still prefer them for low profile etc...

I prefer cantis myself, but you have to be sure the version you select will work with your front fork. Almost anything can be sorted out, but for a touring bike with cantis I prefer a little more width to my front fork so I have easy canti mounting, and fender mounting, etc...