radiant foil barriers...sheets, boards, foam backed, wood, etc. which is best?

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We have decided to put radiant foil barriers in our attic after discovering their existence. It will be a DIY project. We live in Atlanta GA, the temp in the attic gets above 120 degrees for three months or longer. I have noticed most barriers reflect abt.97%and was wondering if the roll form was a good choice for durability or whether it would make better sense to spend more and get the paneled type? The floor is already insulated with fiberglass but our room ceilings are still warm to touch.