I have taken 5 yearly 1 week tours on my Bachetta Strada. I love it! The Strada, if you're not familiar, is a twin 26-inch wheel recumbent, or a 'high-racer'. Thus, it's built mostly for speed. I toured a couple of years with panniers, which worked out ok, using a rear rack and a mid-ship rack that fit under the seat. It was a little bulky, and the weight needed to be in the middle or my front wheel was way too light.
Two years ago I researched trailers. The industry standard is the one-wheel trailer, the most common of which is the B.O.B. (beast of burden). I found I did not like the balance of the bike, it tends to yaw back and forth. Upright cyclists told me they had this too, but got used to it. With the recumbent position lacking a 'three point' balance of the upright, I decided that the movement was not safe. I researched two-wheel trailers, and found a great one made by Wike, a Canadian company. They make a lot of cool trailers, like jogging trailers that can push a full size handicapped adult. The biking cargo trailer is as light as the BOB, very steady, holds upwards of 45 pounds easily, is very waterproof, is a cool bright orange color, and, if you can't tell from my description, I'm very happy with it. Burley makes a two wheeled cargo trailer called the Nomad, which I think is a tad heavier.
I don't have your balance issues, but my experience is that the two wheeled trailer under load actually steadies the bike. I feel more comfortable doing steep downhills with the trailer going over 40 mph.
If you have other questions, feel free to ask. Have a great trip.