I have heard of it being done, but don't know what all was involved. Probably pretty involved. If you do come up with a plan, it'd be great if you could post photos and info as you progress. Good Luck!
From a compilation of other builders, it's my understanding that the best setup for steering breaks is the use of two, separate brake master cylinders plumbed to rear calipers and rotors that work the rears. In the long run it may be a better option price wise too.