I need some suggestions on where to get or even how to make a better skid plate. The whole underside is exposed and I don't want to smash my oil pan or anything while off-roading. If anyone has done anything better than what the Jeeps came with, which are basically a piece of cloth, let me know.
Thanks!

 

That piece of cloth isn't a skid plate. Three skid plates were available as a factory option on XJs: front (behind the bumper), transfer case, and fuel tank. There are many aftermarket options available that provide the same or better protection.

 

I can vouch that the factory front skid is quite heavy. But it was intended more to protect your steering components.

Ive seen a guy on here weld a big thick piece of steel onto his oil pan. as Spock would say, "crude methods, but effective".