Neil -
The short version -
If I would have mounted a front rack on the Navigator, we wouldn't have used the trailer(s). The first couple of years we traveled "heavy/bulky". I usually limit my rides to 30 miles per day max on rail/trails. That's just my comfort level, and for us, the journey is the objective -- not the destination. I'm sure if you divy up the gear between you and your evil twin (or are you the evil twin?) you could get by just using the Navigator with rear panniers. I've done many overnight/weekend sections and haven't had a problem breaking spokes, if that's one of your concerns.
The long version (and waaaay more info you could possibly care about)--
Up until 2004 I had done mostly day trips along the C&O canal and sections of the GAP. In 2004 we borrowed a used kid's trailer (I also had things shoved in two panniers), and we started a mother/daughter tradition of riding down the canal towpath. Libby was 10, so I carried all of the gear. We planned on 15-20 miles per day, with activities to keep her occupied. Our shortest day riding was the first day when the trailer suffered a catatrophic failure and had to be put out of it's (and our) misery. It lasted all of 9 miles... Our longest day that year was 28 miles from Little Orleans Campground to Fort Frederick.
OK - a little about me. I am very overwight, and have had total knee replacements in both knees. I am also blessed with having epilepsy due to head trauma after a major auto accident. There's a medical device implanted in my chest wall called a vagus nerve stimulator that connects to the vagus nerve leading to my brain. It is used as an adjunct therapy with medication. When I am active it also interferes with my breathing... every 5 minutes, without fail, 24/7, unless I choose to temporarily disable it. I didn't the first trip out, but do now. My longest day riding was just over 50 miles when Libby and I rode with a boy scout troop (2006). It was a long day for me, and I just didn't enjoy it. I do much better when I don't have to make it to a certain place at a specific time.
We traveled heavy that first (and second) year. We referred to the cargo trailer as our "RV"... used a three person dome tent, carried MREs that first year, fishing rods and tackle (in 2005 I even brought my mandolin), heavy self-inflating mattresses. I could not have made it without the trailer, our gear was big and bulky. The Navigator and trailer setup worked well... I also had a rack trunk and handlebar bag.
I started taking weekend trips on the canal and GAP, usually alone -- Meyersdale to Confluence, Confluence to Connellsville was (and still is) one of my favorite trips -- in 30 mile chunks. When Libby and I ride this section, we ditch the trailer, and fit our gear into rear panniers and rack trunks. (We've gotten better about bringing everything but the kitchen sink, but still take some fishing gear lashed onto the bikes) She uses a basket instead of a handlebar bag. I thought about getting a rack for a front suspension bike (Old Man Mountain?) but the opportunity arose to get the Randonnee, and I jumped at it.
We've lightened up our gear somewhat, but we still go as comfortably as we can. The self-inflating pads were replaced with Big Agnes Insulated Air Core mats, I now use a down bag, the 3-man dome tent was replaced with a Eureka Zeus 2 Exo (a single wall backpacking tent that I had condensation problems with), then hammocks, then a cheap ALPS Mounteering tent. We took the hammocks in 2006, but there weren't satisfactory trees in some of the hiker/bikers (big diameter, far apart). Fortunately for us we had stowed the Zeus in the SAG wagon. Oh, and we no longer carry MREs... except one for an emergency meal.
BTW - have you resolved your stove dilemma, and do you need any other gear?
Judy