I have a Tubus Tara front rack, as well, and highly recommend it. The Tara is designed to attach to the mid-fork mount on your front fork and the dropout eyelets. It is simple to install and remove.

I also have a Nitto M-12 front rack, which attaches to the cantilever brake posts and the fork crown. I would not recommend it for touring unless you plan to carry almost all of your gear in the rear panniers and only need space for a few items in the front. One thing I don't like about the Nitto is that if you attach a bag to it, it obscures your view of the front tire. It also places the weight higher than front panniers, which affects handling more.