Nitrous with a 4spd

I had it on my street car and I simply had the on/off on the pistol grip. I'd let off the button to shift.

I would need it to be an automatic set up Possibaly set up on the clutch somewhere. I do not trust myself to let off the button on the shifter. It could be catastrophic if I screwed up. Bouncing off the limiter with NOS full bore. OUCH!!!!!!!!!!