Depends on what you use your jeep to do... If you plan on trails or rocks you might want to look at a drive shafts ...just to start, but its not needed right now..
The problem that is caused when you lift a 2 dr JK is the drastic increase in pinion angles
On the front what eats the drive shaft is when you flex it comes down , hits the cross member and eats the rubber boot, then its a down hill degrade till you need to replace it, and its also the pinion angles, the stock drive shafts run a style of CV boot design and are really not designed to work at these angles. Thus replacing them with standard u-joint style drive shafts will get you optimum life .....
But like all thing Jeeps are always a work in progress and you can upgrade along the way..