Get the official Rally pads, made by Ferodo, I believe it is the "DS2500" compound, likely much cheaper if you can buy them direct from Ferodo rather than Daihatsu.

Discs, Any reputable brand standard replacements will be just fine. Mintex, National, Delphi-Lockheed.

Don't need to get sucked into buying the grooved / drilled type, they do nothing on a road car, and they are just standard discs that the company grooves/drills.

And I bet you they don't balance them like they were when they came out the box!

They do look nice though when the wheel shows the disc, Just don't expect braking gains from just a disc.

Improvments are mostly to be found from the pad compound, Unless you also upgrade to a larger diameter disc and different caliper..such as a 4-pot wilwood.