Yeah...I prefer cold rolled steel to galvanized for patch panels as well. It is easier to work with and produces less welding spatter.
As far as ventilating in your home garage...an open window or door, a fan and a respirator does the trick. It works for me.
Like I said, no skin off my nose if someone wants to save a nickel and buy galvanized sheets from a home improvement store instead of something that doesn't have potential health issues associated with it.
You're not saving anything buying galvanized over regular steel, the cost is about 30 percent more.
Also, there aren't any other metals that don't have potential health issues associated with welding them.
Happy safe welding
