Cutting springs soon new donuts

[English Bulldog]

Cutting Springs Soon
I have to drive up to Los Angeles to see my wheel guy. He will cut my springs and install the KMAC rear camber adjuster.

I am thinking that I should go with the 1 nub spring donuts on the springs because this is the thinnest and will get me down the farthest while conserving the most spring.

My question is does this make sense and where to buy the donuts?

Also, when he puts in the rear KMAC unit, are there some bushings that I should put in and which bushings since maybe he has to pull it apart anyway. (and I might as well put in some new parts while doing this.)

Which bushings are these and where to buy these?

1981 300CD
Thank you very much.