Rebuilding my front end....

[SAF_Capri]

Over winter im looking at rebuilding, restoring my front end, being a capri the wing fronts have some rot, the car was restored 3 years ago, but signs are showing now...rather than fit new wings im looking to weld plate then seal them? is this feasible with a good filler/compound? the holes are 2p size,..if so what filler is worth using and then what is the best primer to use prior to going to paint? its getting an engine change same time, so wings will be left prime for around a month.

[SAF_Capri]

simply put.... are the products like rustbuster worth it? will they prevent a rebuild in a few years? keeping my car rust free so i dont have to worry?...obviously things need maintaining nad checking tho.