The Hobart Handler 190 is a nice machine. I bought one for my Son-in-law and used it for some fabrication on his Land Cruiser. I didn't have an opportunity to use it for sheet metal, but I believe it'll do the job. I'd suggest using 0.023 wire for that. Definitely clean the rust off before welding.
If you use flux core wire, you can get away with a little rust, but even then it's best to have it nice and shiny.
