I would think porcelain would be excellent. I was also considering a Race Deck or similar solution where I could replace tiles easily and not to expensive if limited to a welding area only. I'm also still considering the Race deck border option, where all edges of the garage that stuff gets put on, is on Race Deck then the middle is Epoxy. That makes it very easy to redo the epoxy every couple of years because next to nothing would have to be moved out of the garage.
There was a race deck thread where someone welded on it and was very unhappy. I think it's just smart to cover the floor when welding. If that is too much trouble then leave it and stain and seal the concrete.

