Quadratec..

I bought the plus 4 for a YJ. There good to about 7" on the XJ..

 

Armor

 

I'd seriously say get JKS quick disconnects first. Yes Armor is very important, but you will be way more capable offroad when you unhook your swaybar. Very next should be a Gas & Transfer skid outta the Junk yard.

 

Tow hooks/recovery points

 

winch bumper with winch.

 

Long arms. oh and buying an xj in the first place.

 

i would say best so far would be the electric fan, its the only thing i've done that cost very little (around $45) and helped my mileage and power, it also made driving with the stock 3.55 gears and having 33" tires tolerable. the list would probably go: electric fan, trans cooler, front bumper, rear locker, lift, tires, etc. once i get a selectable front locker and do the regear the major items on the jeep will be done.

 

locker, without question.

 

I third armor....