What from a 2003 WJ should i take for my 2001 XJ? Im going to be taking the seats so far. Anything else that i will be able to use on my XJ?

Power steering pump if it has the 4.7 liter because it is super powerful and runs with more pressure to power a fan or something but it will turn your wheels with ease.. what about the steering knuckles can't you use it for high steer?'

it has the 4.0 engine

Knuckles, calipers, rotors, TRE's if they are in good shape.
The WJ knuckles and calipers go for 200-300 pending condition. And since its an 03, it'll have the update calipers. Calipers are twice the size of stock cherokee calipers.
You could also grab the power steering pump and alot say its an upgrade.
The brake booster is nice, could sell for around 65-75 as its the upgrade dual diaphram version.
Intake manifold.

How's the head? It should be a tupy casting. I may be interested.

Calipers & rotors? Are the front calipers a direct swap for XJ's? I know the rotors wouldn't work, because they have different bolt patterns.

Lower control arms! That's what I would take at least, then again, I do still only have puny stock ones...