Choosing a route is not an easy thing to do when upgrading. Time, money, plans add all into the mix. Based on what you describe as a timeline and plans, I would say do it. In the short term and to the long run, spending the money today will be the least expense. Swapping diffs, doing more gear work, lockers for the limited tire size will probably be more expensive but that really depends on how much you spend on it as well.
Only other place where you can upgrade with minimal amount $$ are in the front axles. Look at upgrading to TJ shafts as they have the 297/760 larger ujoints compared to your 260 ujoints in the YJ shafts. You could also go to alloys as well with them, but why? unless you break them more often...