My advice: dont waste any time and money on these panels. They are just garbage.
Get second hand panels and then we can talk about rust proofing.
That is if the rest of the car is in better shape (whicht may be doubtful).
Then you should flood your doors, sills, bonnet, boot lid and rear quarter panels as well as basically all the holes on the underside of the car with something like fluid film
http://www.marineco.co.uk/fluidfilm.html or Mike Sander's fat or Teroson multi wax.
My guess though, if your panels look like this, the rest of the car will be rotten as well.
So you might want to do yourself a favour and remove the plastic inteieur covers in your boot (the floor and especially the big pieces on the sides. Beneath you see the rear strut towers which are prone to rust and you can also look inside your quarter panels.
If those are rotten, you might as well save yourself the trouble of doing what i said earlier and just get another car. Unless you really like restoration projects.
Hope that helps.
Just remember: what you have there is far beyond touching up and a "repair" respray job will maybe last a year...