Another option to consider would be a 231-300 doubler. With the XJ, you'll have the wheelbase to ensure driveline angles are not an issue. Here is link to the kit.
http://www.pirate4x4.com/forum/motor-tranny-t-case-performance/696803-np231-planetary-crawlbox-box4rocks-499-a.htmlAssuming you already have a 231, you'd be $500 for the kit, roughly $200 for a Dana 300, then another $450 or so if you wanna upgrade the Dana 300 output shaft. With an upgraded shaft, your total cost would be roughy $1100 (about the cost of a 241OR) and this would be super strong.
This would give you a 2.62:1 (Dana 300), 2.72:1 (NP231), and a 7.12:1 low with both low ratios engaged. Also, you be able to later add a 4:1 kit to the Dana 300 to give you 2.72:1, 4:1, and 10.88:1 options.