I am getting my rear lower inner and outer bushings replaced to stop a squeaking noise.

what else should I replace?
The ball joints I was thinking and I don't know.

My Indy also told me the control arm is fine.

 

I just changed the tie rod end and wheel bearing hub and solved the problem. If the ball joints are fine you dont need to change them.

 

Would the control arm have both inner and outer bushings?

 

no just inners... front and rear. It's the rear one that most seem to replace

 

just replace what broken and you be fine