OK, there is clearly some location specific stuff going on here. Apols for calling it a Jeep accepted by the way. THAT is a Colorado. Now it should really have an electric rear diff lock and a mechanical centre diff lock. But, being Irish, I think that you don't get the rear locker. You can put an ARB rear locker in there yes.
Can you put a standard Colorado electric locker in there? No. Well yes you can, but you think that an ARB is pricey!!!
Firstly the axle is actually a different shape, generally and doesn't have the cut out to take the diff with the locking mechanism. Then you need the electrics to fire the locker. These have to integrate with the 4x4 ECU. Then you have to consider the fact thay your porbably have an LSD which need the whole diff from another 90 to work with the electric locker,
OK, you can frig all of that to make it work, but honestly, I see going with the ARB as your option. You also get a stronger carrier too.
Chris