In regard with your small chainring, I would swap the 26t chainring for a 22t. Given the weight and terrain you'll be covering, you'll definitely need it. Your legs will thank you. I met this guy several years ago touring off-road in Colorado with tons of weight in his panniers while crossing very mountainous terrain. A few days into his tour he came down with tendonitis in the knee. He had to quit his tour as this takes several weeks to recover.