I wanted to post an update to this thread, as I completed the work this afternoon. I purchased Moog ball joints and bought a spare set of UCA's from another gracious member. I had a local machine shop swap the new ball joints in so I could replace the UCA's as an assembly to save me time. ($30 well spent, BTW)
I have to say, this was one of the more intimidating, but surprisingly easy bits of maintenance I've done to the truck. You would think replacing a major suspension component would take forever, but I replaced both UCA's and took a test drive in under 3 hours. I don't have any special tools, a lift or any of those luxuries. This was done in my single-car garage with hand tools. It really wasn't difficult at all, and there's lots of room to work in our trucks. I didn't even need the pickle fork I bought for the job; I just hammered on the spindle and the joint popped loose. The new ball joints are great and the car handles much more stably now.
For those searching or considering this maintenance, take heed. Toyota will tell you the UBJ's aren't replaceable - "they're permanently pressed in." Horse crap. They quoted me $1500 to fix the problem. Yah ok.
Buy whatever replacement UBJ you want, tackle it yourself, and save hundreds of dollars. My truck has spent its entire life in the rust belt, and I didn't find anything frozen or seized. A breaker bar took care of anything remotely stubborn. Overall, I'm totally satisfied with the maintenance and sitting pretty with the fact I'll probably never have to do it again.