Hi Jason,
I also have a 95 limited.
The 95 limited comes with a Dana 35c differential. Being a limited, yours will be an LSD diff, which is Limited Slip. It means both rear wheels will engage on slippery surfaces. A noisy diff is not the end of the world. They can howl and rumble for years. If your diff was really popping, crunching or grinding, i would consider swapping it out. Otherwise, just chill and save your money.
$750 is a lot for a Dana 35c. Most Aussie 4.0 XJ's will have this diff and you can virtually give them away. Personally, i think they are fine. I have upgraded mine with 4.88 gears, and ARB locker and Superior chrome moly axles and never had a problem... but that costs a fortune.
Honestly, i would hold off for a while... wait for a low k's cheap diff to pop up.. not from a dealer, but someone wrecking one on GumTree. then swap it out yourself. A few YouTube videos in interim and collect a few tools. Its an easy job..but the diffs are heavy..
Hope you have a strong missus...
Cheers,