Anything is possible when talking sheetmetal replacement. Keep in mind the roof has a curvature to it, so a similarly curved piece will be needed for donor material. Some filler will be needed to block sand out really slick. After priming and painting it will look great. What I don't think you'll like is that once you start driving it, the roof flexes, the sun beats down on it, the filler shrinks, the repaired will show.
If it's just a driver quality car, go for it.