none of that stuff is available, it's all custom... that'll be a minimum of 3 patches, if not 4 or 5... when doing that area, i like to use a minimum of 18 gauge if not 16... first thing you'll need to do is trim back the bad area to solid metal.... than grind or blast it as best you can...
you can use cardboard to make templates for each patch... that forward B-pillar section has the belt attachment that if you need to use will need to be removed, drill a hole thru the patch, then preweld the nut to the patch before installing...
I've done a few of those, Wraenking's was similar, but I am also very tool equipped... you'll need various body tools, from the welder to various grinders to metal cutting implements to c-clamps...
and as always, rust never sleeps... if you patch and leave rust, it will eventually come back.. the more removed the better, obviously blasting is the best alternative.. if that area looks like that, I would take a close look at your tailpan too.... I could walk you thru the patching process, but keep the tool and time requirements in mind... That could take a first timer a week to do a decent job..