The 1250RS eats rear pads so it's not worth fitting top of the line kit. GS Rear Pads by EBC. Fitted to 1200gsa with no problems. Used Ebc pads on other bikes and found them to good quality and long lasting.
EBC Double H Brake Pads - FA447HH
EBC Double-H Sintered Metal Brake Pads FA226HH (2 Packs - Enough for 2 Rotors)
EBC Double-H Sintered Metal Brake Pads FA347HH (2 Packs - Enough for 2 Rotors)
EBC Double-H Sintered Metal Brake Pads FA379HH (2 Packs - Enough for 2 Rotors)
EBC Double-H Sintered Metal Brake Pads FA236HH (2 Packs - Enough for 2 Rotors)
EBC Double-H Sintered Metal Brake Pads FA380HH (2 Packs - Enough for 2 Rotors)