I have not been here for a while, just checked back to see if there had been any progress.
I went through quite a convoluted process to get a handbrake working for drifting.
I sourced an E30 handbrake on the cheap from ebay, ripped apart an old cheapo logitech wheel for the potentiometer & usb electronics then mounted it all on my desk in a pretty ghetto fashion using a few springs to retract the handbrake. It worked well but without a proper cockpit I had to mount the handbrake in a vertical drifty orientation between the wheel & gearstick on my desk. The main thing is fixing the pot to the base of the handbrake at its pivot point for a nice motion.
I cant get any pics atm because the racing desk has loads of junk piled up on it, I was hoping for some inspiration to fire up the old girl.