My answer would be: None...
I purchased the 3M kit and I never use it.
I think it's safer and easier to simply take a sheet of Wet/Dry 3M sand paper and do it by hand.
I would suggest you use 600 grit to start with
Followed by 1200 grit
Finishing with 2000 grit
Then you can polish using your DA with compound and Polish
For protection, either Opti Coat 2.0 or Opti-lens