Detroit soft locker for the rear, you'll get through most stuck situations with just that, and if you really need it, ARB up front will get you through much more!
I like the idea of having a mechanical locker in the rear. You never need to worry much about it, they are extremely reliable and really are maintenance free. ARB air lockers are also fantastic, but requiring a compressor, means you will need electrical to lock it, air lines to get it to work, and those extra pieces just mean more failure points you're prone to. I'm thinking of this from the standpoint that you will most likely be somewhere in the Honduran forests/hills, with no other vehicles to pull you out, and having a rear locker should get you out of most situations, while having the front locker is more of an "oh shit" situation where the rear locker isn't cuttin' it!
This is the setup on my truck, and its worked really well for many years. If you've never had a locker, the rear locker really does a lot of work. Putting the ARB up front really does make obstacles seem like nothing, but it can get you in trouble really quick too! Trails that I did before without the front locker were literally uneventful and nothing to the truck once I did! And that's when it gets "fun"! You start pushing a LOT further than normal, locking all 4 wheels will make you overconfident and that's when you quickly find yourself on your side or in a spot that's impossible to get out of without extra help!
That's just my opinion though! I'm sure others will have differing opinions, but I like having a true locking differential in the rear rather than just a "lock right" type of locker. I've always said to do it right the first time and you'll never regret it.:becky: