The big buck indestructible high HP options are ARB or Detroit Locker. I prefer the Detroit for the rear end, it will handle more shock load than the axles and the new soft lock design has reduced the clunk associated with a true ratcheting locker. The selectable ARB is a favorite for front axle use as Pepe said due to on demand only use allowing normal open differential operation for better road manners and slick surface tracking. The downside of the air locker is the cost of the unit itself, onboard compressor, associated controls and hardware. Also required is a receiver tank filtration dryer for supply air to prevent moisture and oil from migrating into the critical components. I have seen ARBs operated by a regulated nitrogen cylinder which greatly simplifys the system and the reserve capacity of a small nitrogen tank is quite a bit, more than enough for months or operation or topping off after air down for off road use.
You answered my query before I was able to ask
And from personal experience of powering air tools and airing up tires it is about a perfect system, yet simple, as you can get.