KOR:
needs to be 12V to logic power 6-9V (roughly worst case 400mA to be save 500mA)
and 24V to 5V for shift registers on the Output side (2*20mA to be save 50mA)
So, how about using a SMPS for the 12V to 6-9V supply and a linear for the 24 to 5V. A 7805 in a TO220 package might work, even without a heatsink [though it will get quite hot [around 23°C + ambient] -- so if that's an issue, then use a heatsink]. And, on the 7805, follow the datasheet recommendations for the layout and capacitors, etc.