I am a long time tandem rider and owner who has toured on our Burley Bossa Nova multiple times, albeit with a smaller wife or smaller children on the back (stoker) seat. My primary recommendation would be that, after you find a suitable bike for yourself, you make sure to get some tandem miles in before heading off on your tour. Tandem riding, especially with a visually impaired stoker, can be challenging. Adding a bunch of gear to the bike and/or a trailer only make the situation worse.
Every tour I have done on the tandem I have gotten myself and my stoker comfortable during practice rides around town with a "naked" bike. Then I have loaded up the racks and panniers and done multiple test rides with the gear loaded on the bike, just to make sure everything rolled well before we left town. This will save you some frustration during that first week of touring.