Rusted Frame…welder opinion/options

If the location is right where the shock mount is located then you want the section I linked. The one you linked is for the mid-frame and includes the leaf spring bolt and continues about a foot or so toward the rear. I don't think this will reach your issue. See the link I proved which covered the frame section on the upper rear portion.

Also see these similar products from a different maker. Check pricing and shipping for the best one for you. These folks also have installers so check that for where you live.

https://www.autorust.com/safe-t-cap-kits/

In my case I asked my mechanic if he had a reference. Turned out one of the techs did welding on the side.

In this image I think you want the turquoise section. The part you linked is the red section.

 

What is a common gauge that people are using to patch their frames. I guess it depends if your cutting out and replacing or just welding plates over the bad areas which is kinda lazy imo.