ARB quality is unbeatable. The con is that you need an air source. OX lockers use a cable, so they are a more straight forward install. Auburn ECTED locker are electric, but they act as a limited slip when they aren't engaged which means more wear on an axle with hubs that do not disconnect, like your D30.
If you already have the gear setup you need, a lunchbox locker is your best bet for the money (Spartan or Powertrax). The downside is that you cant unlock. It the axle is getting power, its locked. This can be an issue if you want to use 4wd on the road and sometimes it limits your steer in tight spots.
ARB is the most expensive, but for good reason. I would go ARB or just lunchbox lock it. If you do gears at the same time, consider a detroit locker instead of the lunchbox.
Friends dont let friends do DUBS.