As per Old Man Emu, I agree with 88Blownstang. Expensive, but really great. Think about all of those films showing miles, and miles of wash board roads in Australia. ARBUSA.com is a good place to call for your needs should you choose OME.
As per JrTxJ, the idea of Made in India leaf/coil springs reminds me of the super fine steel they use to make the very best, i.e., top 'notch' Gurkha Blades. What those master craftsmen do is to send a boy on a bike, bus, and/or train to a junk yard miles, and miles away in order to scarf off a Mercedes Benz leaf pack, and it is from that steel they fashion their blades.., lol. So, are you taking a chance on quality control? Well, apparently, or apparently not.
My thoughts on XJ parts is fractured, as some after market parts are on both end of the quality spectrum. You can try anything, but it's a coin toss more, and more. Be prepared to face the consequences. Your question is in the arena of a parts acquisition daymare/nightmare.., but you have come to one of the best places to pose your question to. Some of the best XJ'ers around can better clue you in than me. Still, for my hard earned American Dollar, I'd go with the best recommendations you will find here, and my vote is for OME. They have a light, medium, and heavy duty type leaf. However, keeping your stock front coils, and then using OME rear leafs will most likely have your rear end higher than your front end. Used to be called a "California Rake". Good in snow country some say. I used heavy duty, (and their shocks), all around, and haven't looked back since.., but you will pay a high price. If I were to build my XJ, such as found by those in the Modified Section, I'd've gone with even better quality products they mention there.
Maybe you just want something that will last to match whatever your reasoning is. Happy Trails...