Ah, tandem touring:

With a light weight captain and stoker your current wheels may work just fine. Have a bike shop true and re-tension the wheels and check the hub condition. I would also suggest using a wider tire [if you can] than you use for unloaded rides. This gives you the option to ride rougher roads and gravel to more scenic locations at times.
Front racks from Old Man Mountain can be mounted when no braze-ons are available. Other racks can use clamps on the upper portion of the fork.
A tent gives you more options for choosing campsites formal or informal. Flexibility in planning makes for less stress than a rigid itinerary.