Red 1968 Barracuda Coupe Basket Case

might I suggest the mig welder with bootle, figure on using the small mig wire, .023 it requires gas. the flux wire will come in . 035 and larger, and can be hard to weld thin sheetmetal with the larger size wire. and understand, the metal needs to very clean to wire weld.
I would at the minimum figure on a repoped quarter or the patch panels for it. with " skill", you can fab some decent repair panels for other areas.
widen rear wheel wells, move the inner well inward. make a splice to widen it, the rusted outer wheelwell?,:::: make or buy repair pieces for that.
remember Rome was built in a day, it took a LONG holiday weekend with lots of slave labor!?????? good luck.