Dana 30 is plenty good enough in a sub 4,000-pound SUV, especially if built as others have suggested. It's why they continue to manufacture them after 40+ years. Swapping the Dana 30 to say, a Dana 44 will require a lot of fab work, big bucks, or possibly both.
I've seen a Chrysler 8.25 with welded gears stand up to a small block making 500+ horsepower at the crank. In a 1/2 ton truck. On drag slicks. At the strip. So I'd say that's plenty good enough in a small SUV too, again, especially if built. A factory tow package XJ Dana 44 MIGHT be marginally stronger, but also difficult to find. If you absolutely have to have something bigger in the back end, swapping in a Ford 8.8 is a popular choice.