Yes your JK would benefit from a regear. 35's on that old 3.8L with 3.21's would be a nightmare!
Take a look at this package:
KOR Gear Packages with Master Install Kits
I would recommend new bearings and is what comes with this setup. Also, since you have 3.21's, you will need a new carrier as well. Make sure you choose that option. This will be everything you need minus fluid of course.
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