Cutting and sanding/buffing galvanized steel
I would use a 4-1/2"- 5" angle grinder, I have dewalt, bosh, Makita and even a harbor freight. I use the very thin metal cutting disks fro cutting steel all the time, after cutting a pass done at a 90. a quick 45 will take the sharp edges off, if I want to polish or buff I use sanding disks, if I want to take rust off I will use a wire cup brush, in all cases it is a really good idea to wear eye protection , a face shield is even better with a good pair of leather gloves both to protect from the hot sparks from the cut but also from the metal it will get hot also. If you go with a grinder it can also be used for masonary just change disks. I probably have more angle grinders than any other power tool because the are so many uses for them.