You need to contact Bike Friday and find out what is the largest disc diameter they allow on the front forks. I can't imagine needing much more than 160mm and I'd be thinking that would be the maximum anyway.
Looks like the front forks are IS, but apparently BF use a size out in the adapters so for a 160mm disc you'd need a IS to post mount adapter for 180mm, but again, confirm with bike Friday.. The rear looks like post mount, probably for 160mm.
From my experience the Rohloff rotor doesn't play well with BB7 mechanical calipers as it's too stiff, so if you are going cable, use TRP Spykes (they are a better caliper anyway)