Not sure you will find any pep files for foam to Gear of War costumes. However, it is not that hard to use a full paper pep file and convert it to foam yourself. With abit of practise you can do it "on the fly" while making the armor in foam. Keep in mind that you have to think in a new way when working with foam from a pep file.
A tip is to read this guide HERE, it is VERY helpfull in learning how to work with foam.