Swapping in a '98 Durango box is a good upgrade, bolts in and is physically larger inside and out. You can look for one that came with the snowplow package for a little quicker steering ratio, but either is fine.
A friend of mine just put one in and said he can no longer feel the steering resistance from his front OX
locker.
I'm going to put one in my YJ soon, already drilled the PS fitting at the pump for more flow and installed a cooler. I run a front spool and the steering fluid was getting really hot on the trail.