Drive Shaft Question

So, after it's been on for around a year, I'm finally addressing the Check Engine light for the evap leak on the gas cap and fuel filler hose and some kind of solenoid in there somewhere. (Throwing in a new fuel filter while I'm at it too.) I'm also looking at fixing a vibration coming from the drive shaft. I suspect a worn out carrier bearing. Being that the truck is at 300k miles, It's probably due.

My question is if I'm going to replace the carrier bearing, do I go ahead and replace the u-joints as well? The shaft has been vibrating/buffeting for a while and there's sometimes a shock when releasing the brakes from a stoplight when the torque returns to the shaft. The one thing I don't want is to do all the work to replace the carrier bearing and then four months down the line have a u-joint go out due to excessive wear. I have to take the shaft off anyway....sooo.....

Hmm....Maybe I just talked myself into it. Cheap preventative maintenance, and all that! Maybe I just need a few more opinions to reinforce my instinct.

The adage of spend a little more now to prevent spending a lot later is rattling around in my head. What do you guys think?