I properly modded High pinion D30 is probably equal to a stock LP D44. The HP D44 raises the bar, though. Remember that not all D44 tubes are created equal with the HD versions often having a thicker axle tube as well. Tube thickness is an issue on the D30 but trussing or sleeving, both relatively low cost options, can help there. Your 2000's factory front axle is probably a low pinion D30 that is measurably weaker than the high pinion designs used prior to 2000. Note that the TJ also uses the low pinion design as well, though.
Many, many jeepers run 35's with big u-joint axle shafts ( preferably chromo) and trussing/gusseting on a HP D30. As you are looking at re-gearing as well if you do stick with the D30 please look into spending a $100 or so on an earlier HP D30 as the strength upgrade is worth the cost. Compare the cost of doing these upgrades to your current axle versus buying a HP D44 and then modifying it to work with your XJ suspension and steering. Remember to factor in at least matching the rear lug pattern if not the width, as well, to the price of the D44.
That the HP F250 D44 is stronger is a given. If it is worth the price difference you might find between the two options is something that only you can decide.
'91 MJ with some mods
'14 MK without some mods