old man mountain racks fit with disc brakes. I have a slightly used one I could sell you for half price. But you may need to check out their site and check on what extra adapter you need to make it fit with discs. I just took it off a regular brake bike.
PM me if your interested.
I also had planet bike freddy fenders on a my konda dew with discs. I just had to bend the fender supports a little to get around the brakes.