Engine skid plate and steering box skid plate.
Skid Row has a 3/16" thick skid plate, with versions that mount to your control arm and protect the exhaust, or a long arm version that can sit a little higher but does not protect your exhaust.
Jeep Medic has a 1/4" thick plate that is like the Skid Row long arm kit (you can run both with your stock short arm setup).
The Medic is stronger, but heavier. I've not seen a Skid Row fail to protect an engine, but I have seen one that got dented. I would imagine that there are rocks in this world that curse the name of Jeep Medic.
I run the Skid Row, I've only dragged it once, it held up great. Avoid the Warn engine skid, it's 1/8" thick and bends when you come within 2" of a pebble.
For the steering box, about 2 dozen manufacturers make skids and all run about $50. Just get 3/16" steel or thicker. Skid Row, Kilby, Warn, many others.
Eventually, you'll want to replace your gas tank sid and your t-case skid. Both can be replaced with tougher models that provide higher clearance, but both may require additional mods to make them work (a body lift for both, a driveshaft and/or SYE for the t-case skid).