[Speaking as an Air Friday owner...]
Contact Bike Friday about disc brakes on the Pocket Llama. My guess is the forks aren't beefy enough to handle the twisting forces generated by disc brakes.
They might also be able to refer you to Pocket Llama owners, who'd be glad to share their experiences with you. You might even find one in your vicinity who might be willing to let you test-ride theirs.
At one time there were models with suspension forks (a la Cannondale), the Pocket Gnu and the Air Llama. However, they're not on the current list of models.
You might consider the Air Glide, which has a Softride-style beam in place of a top-tube or seat-tube. The beam acts like a suspension. It's similar to my Air Friday, but comes with 406 mm wheels and wider tires.
I've ridden my Air Friday offroad on essentially fire trails, with some ruts and potholes and stretches of crushed rock. I wasn't carrying anything heavier than a 100 oz. hydration pack, but was able to stay with my friends on mountain bikes, much to their amazement.