you use the OEM forester calipers, thats what makes this mod great! the newer lgt calipers are different, thats why you use the brackets from the 2000 lgt/outback, no need to purchase new ones. believe me the lgt vented rotors and calipers perform better, but there is an added cost to those. i could have done aftermarket or brembos too, but i wanted some an improvement to the rear brakes w/out braking the bank!
you'd want forester/wrx calipers. if you are willing to buy new calipers you should do the 05+ LGT calipers so you can upgrade to vented rear rotors.