Hey nicksjeep, are you sure that is a 98 Wrangler back seat? I have a 97 and mine looks a bit different, without that rear bar. But I am not an expert.
I just got brackets and a seat and installed it. This guy's video was helpful in showing what you need and how to install it, you can even see where the seat belts attach:
From my recent experience, these are the mounting brackets you will need:
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