As long as you have strong wheels and you can avoid heel-strike somehow, the Pacer should do you well. I certainly would prefer a rack/panniers setup to pulling a third wheel and a bulky trailer behind me on tour.

You'll likely have heel-strike problems on the pacer with the Tubus Fly, especially if you have feet bigger than size 9. Furthermore, unless you're carrying a very, very light load for your two week tour, the fly will likely be wobbly under the load of two full panniers. This will affect your handling and stress your braze-ons.

The Tubus Logo has a second pannier mounting rail that is further back to allow for more heel clearance. You'll have to get some sort of rubberized p-clamps to make up for the lack of rack braze-ons on the seat stays. I recommend doing business with "The Touring Store".