On the rear you can use any you choose. I think the ARB is the best as you get to choose when it's locked and at other times it's an open diff. The detroit locker is I think the self UNlocking diff, some people like them but I've heard arguaments both ways, they need grip to unlock so in the soft stuff they stay locked and make it hard to steer. The other option is an ATB (auto torque biasing) type diff, I don't remember the brand name (might be the truetrac) but I think Muddyweb uses this in the front of his truck, to good effect. They don't lock up completely but give up to 5:1 torque biasing which helps in the slippery stuff without being harsh enough to bust a CV in the front like a full locker might. The ATB is the best fit-and-forget diff as long as you keep the rubber on the road. Put a wheel in the air and you'll want ARB