Depends on what you want and how much you use the car.
I did all poly bushings in the rear of my 79, except at the housing, in stock arms. Worked great, tightened it up, but about a 100k miles later, they were showing wear again.
My 82 has stock 1980 arms and all original rubber bushings in the rear, with all four arms boxed. It launches nicely with traction bars and an airbag, so even the stock arms can be made to work.
The aftermarket arms are a still a decent upgrade, and much easier than installing the individual bushings though.