Couple things to think about on this. My vote would be whole arms. Poly or OEM? up to you as mentioned earlier for that decision. Do you have a press? If not Poly is the way to go if you go the bush only route. IF you have a legit press then either will be able to be done. If you have a lot of rust on the lower cam/hinge bolt, then whole arms for sure. Be ready with reciprocating saw you may need to cut the arms. Look on Utube or on Disco3uk.com for a step by step process.
I didn't have time to do either unfortunately when I did my ball joints Upper and Lower front only. and I had to replace the BJ's for annual inspection, so chose the long road home. Fortunately my Vehicle is from Florida, not much road salts down there.
I expect that when the BJ's wear out, I will replace the whole control arm and go ahead and do the back as well. Got a guy who will do it as a side project, and has given me a great price for labor, if I buy the parts and help out.
Looking at probably doing them sometime in March of 2021, unless wear progresses faster than expected.
Where are you at in NC, if you are near Carolina Beach/Wilmington I can hook you up with this guy I know.