Re: R&P and Locker
You didn't ask, but I'll answer anyway; I wouldn't spend the money for a locker for a D30. It isn't difficult or expensive to put a D44 in front, even if you have to narrow it. I bought two, combined them into one and narrowed it for about $350, including new brakes and seals.
A D30 will take a fair amount of abuse if you're lucky, but if you're not, it can also break without being significantly abused. I shucked a handfull of teeth off the ring gear trying to back uphill out of a muddy ditch. And that was without a locker increasing the stress on the ring and pinion.
Also, if it's driven much on the street you should strongly consider a selectable locker for the front - ARB, Eaton E-locker, Detroit Electrac or Ox, if the Ox is even being made any more.