I was going to ask about your rock sliders too, but read that they came with the Jeep.
I think they are these.
https://white-knuckleoffroad.com/product/jeep-wrangler-lj-2004-2006-rock-sliders/
There are not many options out there for LJs unless you want to drill into the body. These run from ~$450 bare metal and $610 powder coated depending on the tube you choose.
If you're worried about the drill and tap, take them off an run the long drill bit through the holes to the other side of the frame, then put a grade 8 bolt through the frame and fasten it to both sides with large and lock washers If you have plate laying around you could even put a reinforcing plate on it if you plan on hard bashing. Though the more you reinforce the frame, the more force gets transferred to it and the more likely it is to bend under extreme load. I learned in pipe support design that sometimes more rigid structures aren't necessary better than more flexible structures. Loads go to the most rigid point unless something breaks before the load gets there.