Better the gas engine than the diesel.
The wheelchair lift has "safeties" built in.
There are a few different things that the manufacturers build in to prevent it from opening when going down the road.
Its hard to get a mental picture on this but I bypassed the safeties in mine by jumping the solenoid hot on the lift to the main power all inside the lift power/junction box, bypassing the "key on only" lift power wire coming from the front console.
The lift will work now if the door is closed and while in motion but I know that and will not try anything stoopid while in motion.
Good luck on your new project...