Congrats on your purchase, and welcome to the forums. You will find a ton of info in the Tech sticky located in the XJ tech forum.
Best this best that, depends greatly on your budget, also where/how you wheel, how big you want to go, tire size, mechanical ability, and so on...
Spend some time looking through the Lift thread to get an idea of what you might like. Talking with people in your area will also help in deciding what setups work under those conditions.
No body lifts are available anyway, as the XJ has a unibody