I was reading 4x4 articles and I came across this: http://www.4x4wire.com/toyota/reviews/parking_brake/
It's a disk brake that mounts to the back of yout T-case and acts as your parking brake (the Toyota guys use it when they convert to disk rear brakes..)
but I can't find these parking brake kits for anything except Toyota's, anyone seen one for an F150?
Any help would be appreciated - thanx!

 

If you are worried about a parking brake just get a brakelock.

http://www.brakelock.com/