Motorcycle and Scooter appreciation

I need a new rear disc for my triumph scrambler as the old one is Warped from careless disclock + riding away.

Two questions;

1. Any recommendations for a rear disc brand? Was thinking of these
   
2. Do I need to change the rear pads? From memory they are fine. Assuming it's not a chain and chainrings deal, but thought it was worth an ask.
   
   

Cheers.