I'm not sure what Bud's is selling, but I would recommend using a Zeltec or Sanden compressor.
My partner has a 280SL (1971) and he has had a fair amount of problems keeping the engine temp down. He had to have a special radiator made with a thicker core and an electric auxiliary fan. It was quite a job mounting it as there is very little space.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician