Ferodo pads are the worse you can use. While I don't care much for Bendix standard pads, their metal kings are a good pad for hard street use and in my experience do not dust up much or squeak.
Providing you can get pads to suit a RA28, Padgid, Endless and EBC are great pads, but as you buy higher performance pads their first up cold performance will drop off.
Rather than DBA slotted rotors and expensive pads, have you considered doing the Corona strut / Pug vented rotor / Hilux 4 pot brake upgrade for your car ?
I did it to my RA23 and braking performance improved 70% over standard.
Don't ask, use Search on this forum.
This upgrade has been covered a zillion times, and its worth reading all the threads to become a full bottle on it.
Mitch.