300zx body repair

Just bought a 1990 300zx NA auto 2 seater. Near the drivers-side door on the bottom end of the body there is some rust bubbling that turns into fullblown cancer near the wheel well.

I know that I need to grind away the cancer, but I don’t have a welder nor the money to pay to have this professionaly done. So I’ve put together the following options.

  1. Cut out rusted out area from body. Treat with some kind of rust converter & rust stopper. Cut some sheet metal and apply behind the body with jb weld or some kind of wet weld and fill in from the front with fiberglass/bondo and try to reshape.

  2. Cut out rusted area and treat then wet weld/rivert some sheet metal from behind again for some kind of stability and throw a side skirt over that will cover the area.

Opinions?

P.S. No mechanical/body work experience… but I’m feelin lucky!