I have sourced one of my old suppliers -
www.porterfield-brakes.com/ and they tell me they have pads available for the SRT8s.
R4-S performance street pads
Front SRT-8 R4-S $259.95
Rear AP 592.15 R4-S $169.95
I have requested some additional information about the pads and rotors which I will post as soon as I get it.