IMHO, the best way is to cut out the offending section, and fab a replacement peice. I would size it to fit with a slight gap, and butt weld it in. It's a more "stock" repair, but it also eliminates the rust issues that can accomany lap welding.
On the pinch weld, I would drill holes on my replacement peice, then "rosette" weld with a mig which is the best field method to replicate the factroy spot welds.
Use a weldable primer before you join those peices to protect the unwelded internal peices, and a good seam sealer to make the repair last.
That said, most people will just cut a peice and slap it on there, and nobody would blink and eye, myself included.
I would raise an eyebrow at a long peice of channel that runs the length of the rockers as I have seen on some cars. (I was told they were 'Jacking points')
