The ball joints on the UCAs are bad or the bushings at the mounts? Either way, depending on what your time is worth to you etc, it might be worth changing the whole arm.
I can offer you my opinion. I would change the whole arm. They are relatively cheap on amazon.com or rockauto.com and come with brand new bushings and ball joints already installed so you don't have to fight those in and out of the old arms. Replacing an upper control arm is easy so for me that's worth it.
Probably get a set for free from someone who added aftermarket UCA's. I'm sure there are a bunch lying around in people's garages. But I do not believe that you can change the bushings... But I'm not 100%.