If you are comfortable riding the bikes for hours per day then there is no reason not to tour on them.
I am not too familiar with modern Trek road bikes, but it may lend itself to frame and seatpost packs rather than racks and panniers. Does it have rack mounts on the frame and fork?
Also, if the bike has lightweight low-spoke count wheels (like most modern road bikes) then it might be a good idea to get some more stout wheels built for it.
As for the 6700, it's likely good to go as-is. Bolt some racks to it and hit the road. The similar thought about wheels, though - if the 6700 has many many hard off-road miles on it, maybe re-spoke the wheels with new spoke, at least the rear which carries most of the load - spokes can suffer fatigue failure after long heavy use.